I have been 3 times at North Cape with own car from Germany - long way. Not so much to explore on Magerøya island.
Likely one of the companies you speak of is this?
When do you plan to travel?
You wrote about "port day in Honningsvag" - therefore I assume that you will not be there to see the midnight sun? This photo shows you the sun stand at midnight when I was there. If you are there over night - I recommend the late evening and / or midnight.
Guide: what do you expect from the guide? Besides the typical information ("more reindeers than inhabitants" ...) that is in printed versions the guide shall share information and experience what means living up there. Navigation is not needed because the street options are very limited. Net driving time Honningsvag - North Cape shall be 45 minutes each way; so the guide has enough time to entertain for a while because you will only see a beautiful barren landscape without trees - maybe reindeers on the way (photo)..
If the group is very interested in Sami life then this part makes sense - well knowing that Kautokeino is the Norwegian center of Sami culture which is a different way of society and common living. I also found a very different way of housing.
Just to check: Is the entrance fee to North Cape included in the booking fee for the bus?
btw: we liked the food in restaurant Havly.
Please share a report after your trip. This halps other people on the forum.