Welcome Benjie!Nice to see another person getting into flat! Like you, I took many years off from riding and ended up here. Though, I'm almost 45 and got back into riding about 4-5 years ago (after about 23 years away). Don't worry about the age. And, laugh at all the "old" people tell you that you're too old to be riding a "kids" bike. Honestly, you'll find that a lot of people will be impressed with what you do. Though, there are some that will give you crap for riding. But, yeah... that's more on them than anything else.
Yeah, I too had to adjust to the freecoaster when I started riding again. It's well worth the adjustment though. I couldn't imagine going back to cassette and riding flat.
As a heads up, this forum is pretty quiet it seems. Though, there are a few regulars (I check it pretty much daily but don't post a ton) and there's definitely some riders in here that have ridden a long time and have some good input/feedback/answers to any questions you might have.cheers,
Tim