Also there are some Posts here in Forum about the P2P Server from Dragagon. He does a weekly Update which might be helpful to decide. Smuggler's Paradise weekly update!
Oh goodness, those weekly updates are so endearing. Dragagon is putting so much effort into those and I love it.
I appreciate these <3
You're more than welcome to visit on P2P and see how that rolls around

We're a tight community daily on discord chatting and talking. Anyone's welcome.
To go deeper into your specific questions;
Is the levelling experience enjoyable?
Depends wether you are fine with catching up on lore or speedlevel. They removed Time Void from speedlevelling so it's back to regular questing now. Could get fun to minmax and learn what to skip and what to do, but in the bigger picture I'd call it boring

Allods need a levelsquish like WOW had.
Or a better story interaction like FFXIV.
Is P2P the way to go to meet cool people and get the most out of the gameplay?
I'd say you'll get more game for your buck with us than in F2P, but that coming from me is biased ;D So imma leave that on the side!
I cannot imagine new players arriving into F2P and getting into endgame content duo to CS requirements? Unless the few guilds doing those got softer on that?
How long does it take to explore the map and reach max level?
If you're new, it's safe to say 2 weeks. Last Lucky Moments, we had Xaero level from 1 to 100 in 8 hours. It's quite some difference but it's knowing the minmax I mentioned before.
Is group content fun or does it get elitist and difficult when you are by yourself?
It's fun, easy to get into! Has some learning curve but anyone can learn it

Ask all that comes up, we're not far away.
P2P discord for P2P related things.