Welcome to what is IMO the friendliest place around to discuss biking.
I’m with you on the ‘don’t want to break anything’ style of riding, but don’t let age or condition/physical issues slow you down. There’s no harm in riding the more gnarly trails – you can always push it through the stuff that’s more than you’re willing to risk. The rewards (scenery, or sense of acheivement when you finally nail something you couldn’t do a couple months ago) on the more gnarly trails are very often worth the time pushing.
Regarding the politics – I’ll take a pass; this isn’t the place… I will say that I’m not a happy camper this year.
Good luck with the recovery from the bypass. I hope MTB plays a substantial part in that quest, and becomes or remains a passion.