I have heard that everything we do in this process is evaluative. Including how we interact with EVERYONE. The schedulers, the security people at the site, interns at the site that we know from our own programs. It is all part of the evaluation, whether it is formal or not.
I'd say that, at least in my experience, it's basically just like grad school interviews; sort of an, "anything you say can and will be used against you" situation. Not necessarily in as punitive a sense as that, but if you're exceedingly rude in interacting with folks at the site and it's noticed, then yes, it will likely be factored into your ranking decision. Beyond that, though, I really doubt anyone's going to be handing out interviewee rating forms to security guards, the people who delivered lunch, etc. Just do what you'd normally do anyway--conduct yourself professionally, treat everyone with respect, be genuinely interested in the site, and you'll be fine.
As for capping the number of applications--as with Ollie, I'd support it. It's not going to level the playing field in all respects, but in reality, I don't think the playing field
should be leveled all-around; some people are simply going to be better-prepared, better-trained, and/or will have stronger CVs than others. And that's ok. We all make choices with respect to which programs we attend and how we spend our time while there, and folks should be rewarded for being efficient/productive and/or going above and beyond in their training. In my mind, though, capping the number of applications would at least take some amount of pressure off of applicants, since then those folks who might be thinking that they
need to apply to 20-25 sites instead of the 15-17 on which they were initially planning wouldn't have to worry about it because no one can apply to more than XX programs. As was previously mentioned, it'd also reduce the review burden on sites, which (at least in my experience) want to spend more time than they're sometimes able looking over applications.