We bought our boat in August 2019 and I gutted it over the winter and refinished the entire interior of the boat. Everyone has their own method and frankly, it makes for some great reading. You need to use the method that makes you happy.
As for me, for years now I've used spar varnish (satin) on my boat interiors with no problems. I did use a two part teak cleaner on all the parts removed from the boat and also on those that I didn't remove, I believe ours had been coated in teak oil and teak cleaner is all it needed to remove the old coating(s) It's a VERY messy process to do it this way (in the boat) but the results were worth it in my opinion. The interior teak brightened right up and after some lite sanding it finished up nicely, just be sure to let it dry completely after the teak cleaning process. .
Also, be very careful sanding any of the bulkheads, that's a teak verneer plywood and it is very, very thin so don't get carried away with a sander of you will most certainly regret it.
The interiors of our Catalina's are built as components and then installed, so getting any parts out isn't as tough as disassembling a boat that has cabinets that were built in place and are generally much harder to disassemble.
Some teak bungs will need to be removed and other components also removed to get at the galley counter top. The counter tops themselves are screwed in from underneath, all of them are like this and depending on the components you have to remove, it really wasn't the hardest part of the job IMHO. Sinks seem to be held in place with silicone caulk so that needs to be cut to remove them and this greatly increases access to the screws for the counter tops.
You'll get lots of ideas as you keep reading and these are just my thoughts. Best of luck if you decide to do this job, it's not a job for the faint of heart but once it's finished (or in this case "refinshed") you'll be able to look with pride on YOUR boat.