I'd say it all depends on the lake. Lakes like Poygan, it's full on combat fishing. Safe distance is usually under 50ft, depending on crowd, but just don't be a jerk. If your gonna fish close, treat the other guys like they're your friend, work together, make the occasional comment on color or marks, plan moves together to cover more ground. Don't be loud, but respectful. If the guy(s) you move in on still want to be jerks, then just do your own thing. It really can be a good way to learn new lakes. But Poygan is a special place where that style of fishing works.
Now, if I'm on a 50 acre lake, and there is 3 people on the whole lake, it's a different ball game. I will usually maintain at least 100 yards, but will sometimes walk over to other groups and chat. More then once I've talked to a group on the ice and ended up fishing with them. I've drilled new holes for guys who have hand augers, and given rides back to shore via 4 wheeler to walkers. It takes nearly nothing to be nice, and it sometimes earns you a pile of info.
I've had guys drill my spread before, and I have the same approch, talk to them and be friendly, and if there still jerks, I just keep talking, and try to be the most annoying nice guy until they submit and leave or I decide the spot isn't producing and let them have it. Lol. Most guys get the point.
But to answer your initial question, if the permanent shack is empty, I'd drill as close as I want, if they show up and are decent, I might move away a little, but if they're jerks, I stay put. Guides can be the biggest jerks, so definitely call the DNR and report them if they harrass you, no room for that, IMO.