I'd say the game is much tougher than it use to be because there are less players in the sky. This means finding balanced fights is harder. There's a lot of players above "noob" ratings so there isn't so many easy sticks to shoot down. On top of that, many many players still stick to the easy mode trainers which makes the game even tougher for players. I've seen way too many vets in 262s and Tempest just zooming around for easy picks and never have to worry about actually using skill to evade a battle. So this is something that has made the game even harder for most players IMO. I still think there are players just trying too hard in the easy BnZ planes. Id love to see more midwar plane usage but "muh $15$ blah blah". I guess I'm one of the few who understands that everyone in a tempest, 262, and 190D, makes for a slower boring gameplay. So you just really have to be more patient and allow these guys to make a mistake BnZing you, or you get to 20k yourself and try to get them off guard but it just takes more patience and SA understanding to fight all of these super late war planes on top of them mostly being very good Vet pilots.
Is it safe for a P40? Only if you really know what you are doing. I have really enjoyed flying the P40 the last 3-4 months. You have to be really patient getting alt. The 50s don't work like normal 50s, for some reason it takes like 100 50s to bring anything down so that makes it tough. It does however out turn a lot of planes and is very quite balanced. I love flying it, but only if my team has the advantage in the fight. If your side is not winning the battle, than it's very tough to stay alive when the other side is jumping you with 3 190Ds and a spit16 and you have no fighter help. So it's really a very Situational plane but its one of my favorites!
Anyway, we need more sticks in the skies so come back and give it a shot and just have fun and don't take it too seriously because the MA is a very unforgiving place and it's not a fair match up ever. If you want fair matchups, the special events like FSO and scenarios are the place for you.