Windsor, Hampton Court and The Theatre

Q1- I think I'm the only person on this forum who would take the £3 bus 703 (or 8) from Heathrow to Windsor- both of which leave from T5 (so the free rail transfer is the easy way to do it). It is ingrained on here that the only way to make that trip is by taxi, which of course leaves from T3- so simpler.
Q3- The price from Windsor Riverside to Waterloo is the same on day off as in advance- and you can pay by contactless (no price difference, to Paddington from Central contactless is cheaper).
Or, in one direction, take the £3 #702 bus to Victoria to see different scenery.
If I was going to the London Transport Museum I might think about the bus back to Heathrow, then the Piccadilly line direct.
Q5- No the train from Windsor to Hampton Wick is not direct- change at Twickenham or Richmond or onto red London bus #216 at Staines- calls at Hampton Court and Hampton Wick.
In any event no advance purchase of tickets needed.
Q7-Plenty of taxis in Windsor, so taxi or Uber.
Q8- Yes that's easiest, but the key is to stay outside the Heathrow drop zone where you pay a fee to drop off.
Q9- a bit complicated. Basically my advanced algorithm is that anywhere within London Zones 1 to 9 basically is fixed pricing. Anywhere beyond that up to around 30 to 40 miles out of London has fixed pricing, but also super off peak Pricing (called Evening Day out on SWR, anytime after 12 noon, walk up fare) is cheaper still. Beyond that is advance fares. It's more subtle than that, but a very good rule of thumb.

As an example in 3 weeks time I expect to go from Salisbury to Guildford on a day trip. Outbound is local bus. But the way back is by train. The way the fares work it is cheaper for me to go on from Guildford to Heathrow (or even Gatwick) then back on Advance Fares rather than straight back from Guildford to Salisbury. It just takes longer. In practice the easiest solution (and cheaper still, and most fun) appears to be to drop down to Portsmouth for the train to Salisbury. None of which makes much sense but is how the system works.
And at any time it is cheaper if booked in advance to go from London to Salisbury than it is to go from London to Basingstoke (closer to London, on the same line).

Regarding food near St Martin's Theatre, if you're looking for a pub I think I would go for Lamb and Flag (Rose Street). I also like Fuller's pubs for food so you can see which are near you: https://www.fullers.co.uk/pubs/pub-finder/london

I know you said pub food, but the theatre is also very close to Dishoom if you're interested in Indian food. They do take reservations for pre theatre.

Hi isn31c! I would! Have done so! It’s such a great “hack.” :-)

Must echo Cat VH about Dishoom: the food is wonderful! Try the house black dal. It’s insane: https://www.theguardian.com/food/2019/sep/07/four-classic-indian-recipes-dishoom-chaat-dal-salad-jackfruit-biyani-chicken-makhani-curry

Pubs in Windsor: we like the Waterman’s Arms and the Two Brewers. Do avoid the King and Castle pub on the high street - it’s immense and touristy (it’s a ‘Spoons) - but if you dart into the Duchess of Cambridge, that’s quite a nice place for a pint.

We like Côte in Eton for a meal. It’s a chain, but good quality, and good selection. Also recommended (by friends of ours - we haven’t visited yet) is Meat at the Parish. It’s a steakhouse, so not sure it fits your brief, but it gets excellent reviews: https://www.meatattheparish.com/

using Stuart's most excellent numbering system -

Q9 - I use an APP. That's Advance Phalange Percussion. (typing)

I check the price at the time and date I want to travel and then I check the price same time today or tomorrow. Pretty much foolproof.

Q5 - Unless you want a scenic but quite long walk through the Home Park before you get around to the entrance in front of the Palace near the river using Hampton Wick, conventional wisdom is train to Hampton Court, just over the Thames bridge form the entrance. Change at Surbiton, I think.

Q3 - To go all the way into the Big Smoke I don't think I'd do it on service bus, I'd use the little shuttle from Windsor & Eton [EDIT -left off the word "Central"] to Slough and then Elizabeth Line to Tottenham Court Road and Northern Line to Leicester Square and then an easy stroll to Covent Garden.

I’ll add a third recommendation for Dishoom. And I agree about the black dal.

This is great information and advice, and I really appreciate the recommendations. Thank you!