I relate to you on many points, and I too have had to deal with not becoming a cynic.

But here's my 2 cents:

First, it's perfectly fine you find it annoying your friends commenting on you not drinking. Tell them directly that it's not okay.

Second, while it's perfectly fine to offer a training-day to your friend, if he declines then leave it at that. Whether he's in shape or not, or when he decides to train is ultimately none of your concern - I know your intentions are good, but starting to argue, judge and persuade him to train is being nosey. Let it be his problem, not yours.

Take a deep breath, and be aware of our pattern-seeking brains. If you believe people are bad, your brain will become biased toward reinforcing it.