When saying "league" you and I might mean very different things. What should be no different is that we all need to communicate with our own league group, so that everyone understands where the lines are drawn. I often run a casual/recreational league in which our adherence to PDGA rules is rather loose - especially in using markers.
On the issue of talking and moving while others are shooting, there is a wide variance of tolerance, and that especially needs to be expressed within the group.
Once the lines have been clearly drawn they need to be enforced within the group first. If a TD sees problems which cross between groups an official warning, and then a penalty would be in order, especially if there was a recent reminder.
Having said that, I've never assessed a penalty, and I don't even recall an "official warning" on a courtesy violation. Most players want to do the right thing, and simply need to be educated.
We play our leagues by the PDGA rules with the exceptions being.....correctly marking the lie...we're loose on that....when it comes to flipping a disc over as opposed to using a mini.....or not marking at all when it's a total gimmie. This rule really doesn't effect the outcome of the game.
We're fairly loose on completing the hole as defined by releasing the disc and the disc being at rest in the basket...a lot of times a drop in will just be conceded..."pick up....slap chains....move on" This varies somewhat on weather conditions....what's on the line....who's making the shot...lmao...yeah I've seen misses from 3 feet!!!
Generally most of our experienced players will educate the newer players to all the correct rules during play...not too many penalties are handed out...even the correct procedure for marking a lie is usually discussed...followed by "it's ok to flip your disc here....just remember not to do it that way in a sanctioned event"
Another thing we have been fairly laxxed on....is If a player asks and wants to throw another shot to see what a new disc will do or throws a second putt in disgust when they dank an easy one. If it's not holding up the round or becoming a nuisance..then usually not a biggie. We definitely don't encourage it though...at least I don't. I feel like a player should practice putting before the round...not during...generally I don't say too much unless it's becoming a nuisance or effecting mine or other players routines in the group.