3 full days in Galway

I can't offer much advice because we always have a rental car in Ireland. The most interesting stuff to us is out in between towns. That's especially true for Galway.

Ignoring that slight bias, O'Connor's Pub is right in Salt Hill and is the location of the web-famous video of Galway Girl by Ed Sheeran.
We always stay in the city and end up at The Crane Bar. Neither have TVs so people are talking or playing/listening to music.

We rented bicycles on Inishmore, which makes the island much less strenuous. I'm now at the age where an e-bike would be better.
I'd recommend spending the night, but it would mean going there first to avoid having two lodgings. Once the last day trip ferry leaves, the population plummets and the place changes.

We visited the Cliffs via boat rather than endure the crowds at the top. There are Inishmore boats that include the Cliffs, so maybe you could combine the two.

We've been to various places referred to as "the Burren", and they are all fantastic, at least if you like wildflowers. September might be a little less spectacular.

With eight people you could ask about a private tour to the Burren and Cliffs of Moher.Try Galway Tour Company. Looking at FAQs "For custom tours, please get in touch with us via email for quotes." With 8 of you it may not work out that much more expensive?

If you are aftr a guide for a walking tour of Galway City then have a look at the Tours by Locals Galway website. (some guides offer tours to Cliffs of Moher but not for 8 people unfortunately...)

We were in Ireland from mid September to mid October of this year. We took a 3 night trip from Dublin to Galway by train then used Galway Tour Company, as mentioned above for day trips on two consecutive days. Since there were only 3 of us, we booked their regular tours, one north and one south of Galway. They were very easy to work with and I too recommend contacting them about a quote for your group of 8 to do a private tour.

We took a private walking tour of The Burren with Mary O’Dea. She is a local and it was a great experience. Wouldn’t help with the Cliffs of Moher but perhaps you can find a different operator for that?

https://www.hiddenburrenwalks.net/

The Galway Civic Trust offers free guided walking tours of medieval Galway on Tuesdays and Thursdays at 2pm. I realize that you currently have other plans for Tuesday but just in case your plans change, I thought this tour was very interesting, focused on archeological and historical discovery..

I think the walk from Eyre Square to Salthill is more like 30 minutes; I think maybe the bus is 20 minutes. Regardless, it is a very pleasant and easy walk and the bus is convenient too, but if all of your day tours require leaving from Galway center or Eyre Square, staying in Salthill will mean a lot of back forth.

A day trip from Galway to Connemara is also a good consideration. This often includes Connemara National Park and/or Kylemore Abbey. I enjoyed walking the Cliffs of Moher but I did it while staying in Doolin. I have heard that the day trips to the Cliffs from Galway typically just stop at the Cliffs visitor center for a short time where people report crowds and disappointment.

I don't think you have to book ahead for the bus from Dublin Airport to Galway. I'm fairly certain you can just turn up and buy a ticket from the driver. There are three operators serving Galway.

I have heard that the day trips to the Cliffs from Galway typically just stop at the Cliffs visitor center for a short time

I have no experience with the small group tours but the big busses spend a couple of hours at the Cliffs, which is enough time for many people. You just have to check the tour operator schedule.

I don't think you have to book ahead for the bus from Dublin Airport to Galway. I'm fairly certain you can just turn up and buy a ticket from the driver.

This is true. If there is space. But with 8 tired people, I would have tickets already bought. When I was there in May, my bus was full and only 2 more people got on after everyone with a pre-purchased ticket got on. But you need to be sure you can use them for a later bus, in case your flight is delayed. You can definitely get to Galway without pre-purchased tickets, but who wants to wait.

I am no help on the original question though.

Thanks for all the suggestions.
I do wish there was a way to reference particular posts as I reply, but alas!
RE: 3 bus companies that go from the DUB airport to Galway- I only know of Citylink so please let me know of the other two.
RE: Connemara/Kylemore Abbey. My husband and I spent time in Cong on our 1st visit to Ireland. We were young enough to rent a car then so traveled to both those places and beyond. But the friends with us now have never been, so perhaps they'd prefer to head there instead of Inishmore or another Aran Island.
RE: private tour to Burren, Moher and Doolin. I've now heard back from Galway Shuttle as well and their pricing with door-door transportation is looking extremely favorable.

Hopefully your small group tour works out!

I took Citilink Dublin Airport to Galway and am not familiar with other coach lines from the airport.

Bus companies on commercial routes like Dublin Airport runs come and go.

Galway was a fiercely contested route with 3 operators. Before telling you about them I have just checked and it is now down to just Citylink. That cuts out what was serious over capacity.I

SOU is Southampton Airport so effectively that is a domestic flight thus should be straight out of the airport if the flight is on time, on it's second sector of the day. The point being that it may have been delayed on the outbound sector to SOU.

On the return I would for certain book the 7.30 bus or even the 7..15 #761 to cover for any incidents on route - bus breakdown, RTA, road construction work etc.

With it being down to Citylink for bus transportation to/from Galway, should we look into the train?
Or perhaps best to bite the bullet and pay for private transfer.
Speaking of private, for our bespoke tour to Cliffs of Moher, how does this sound?
Early pickup so as to arrive at the Cliffs before the tour busses, lunch in Doolin at a pub off the beaten path, a visit to the Burren Visitor Center (are there short hikes from there?) and back to the Salthill vrbo.

The choice of train or bus is entirely yours. Train service to Galway has recently been enhanced in frequency.

You have the same timing issue as regards booking ahead. On the day train prices are essentially twice what the rates you will see on line for advance bookings. So about 320 Euro in the round for your party, plus taxi to Heuston Station, plus taxi in Galway.

This is the rare exception to the rule for me where with 8 of you I think a private car transfer may well work out cheaper, or at least take the stress out of the issue so otherwise 'pay' for itself.

I am leaning towards the private transfer TO Galway from DUB. Even though we won't be jet-lagged since we're only coming from SOU, the stress of worrying about a flight delay, missing a pre-booked bus and then not having space for us 8 on the next, would be worth the extra euros expense. I think booking the return bus to DUB would work ok.