To try to answer the OP: There really isn't an answer. Some PD's may care, and may simply decline to interview you because of it. Others may interview and see it as "sticking it to the man", and give you "bonus points" for it. Just look at the rest of this thread, and the difference of opinions. IN any case, the main thing to do is to make the rest of your app as good as it can be, not have problems like this again, and perhaps consider doing something to "mitigate" the damage. You could volunteer to work with other students with "professionalism" problems. Or something like that.
To the rest of the discussion: this is one of those unanswerable questions. Some people will say that you should follow the rules, even if those rules are stupid. You chose to go to this school (or, perhaps not, it was the only school you got into), so you need to play by their rules. And if you don't play by their rules, they have every right to punish you for that. If you don't believe in mandatory attendance, then try to get the rules changed via whatever channels are available -- student council, petition the dean, etc. Fix the system, don't just make up your own rules.
Others will say that the right thing to do is fight the system. The rules are stupid, or unfair. If you can get away with it, then go for it. But when you get caught, claiming that the rules were stupid, or that everybody else does it, won't get you far.
My experience is that those people in the latter group are a pain in the ass, and cause problems as residents. There are lots of annoying things you just need to do to get your job done. Completing tasks like mandatory online learning modules which usually make you dumber. Logging your duty hours in a timely fashion so that my program admin doesn't have to chase after you. Getting your vacation requests in on time so that we don't have to re-work the schedule. It is much healthier to do these things, and if they really bother you to help those who run the system find an alternative, if possible.
For the examples listed, I expect that people will have very different thoughts. Let's pretend that I required attendance at conference, and had a sign in sheet.
If Person A signed in Person B (who wasn't attending), both would immediately be brought before my remediation committee. We would review other aspects of their training to date -- looking for evidence of past untruths. I would contact everyone listed on their ERAS applications to confirm all details. Any evidence of a pattern of untruth (any major finding, or several minor findings), and you're fired on the spot. Both would be told that if there were any further similar incidents with lack of truth, no matter how small, they would be fired immediately. Whether the incident was listed in their training summary / letters of recommendation would depend upon the details -- how often this happened, other prior events, etc. I would be more disappointed with Person A than Person B.
If someone signed in and then left repeatedly, they would also be brought to remediation. As I see this as less problematic than the clear falsehoods above, I would probably be less aggressive in hunting for other prior problems. Further similar episodes would likely result in non-renewal, rather than termination.
If someone uses their food stipend to by gift cards, it depends upon whether that's expressly forbidden by the rules. Personally I'd fix this by making it impossible to buy gift cards with a food stipend.
If people steal food from the on call room when they are not on call, that's unacceptable behavior -- again remediation, non-renewal if further problems.
If people steal scrubs to give to other people -- that's stealing. Review their prior behavior, remediation, immediate termination if further problems.
A student telling a faculty member that you enjoyed working with them while you actually hated it -- that's not a professionalism problem. There's a power differential. That's what an anonymous evaluation system is designed to address. If a faculty member told a student that they enjoyed working with them and then gave them a terrible evaluation -- I have a major problem with that. If a faculty member did that to one of my residents, I would talk with them, make sure I have the whole story, and if so tell them it is never to happen again. If it happens again, they are removed from the teaching service -- no more residents.
A resident gets a DUI while not at work -- although a major lapse, it didn't happen at work and I'm not sure it's any of my business. But it is, because it needs to be reported to the Board of Medicine -- so I'm going to hear about it one way or another. The resident will be evaluated for substance abuse, and enrolled in our Board's PHP. They are not put on remediation per se, but any future attendance issues or performance problems will be a serious red flag. Alcoholism is an ADA qualifying diagnosis (not that all DUI's are caused by alcoholics), so there are legal issues I might need to deal with.
Bottom line: This is not a game. You don't get to make up the rules as you go. You are an employee in a big institution, and you need to follow the rules. If you don't, you may get fired even if I want to keep you -- once HR gets involved, I can lose control of the situation. Lying, even over small things, is a very, very bad idea. It is one of the cardinal sins of being a physician, and is hard to recover from.