I have a friend whose daughter just started at Indiana. I can probably get some info for you if you don't get other replies.
My guess is that every college dorm will have wireless internet, as will the classroom buildings, student center, library and so on.
Security is probably a campus-wide standard. If some dorms are locked and accessible only by a scanned card, then they all are.
Convenience is going to be relative depending on where the specific classes are. For example, my son's dorm was not all that convenient to the engineering building but it was to music/arts. I think you could get all kinds of info from the college websites as to how the dorm assignments work - the better dorms (bigger rooms, more modern, etc.) are going to go to those with higher lottery numbers, which means seniors and juniors, then filtering down depending on what percentage of upperclass students live off campus. Some schools have dorms set aside for freshmen, others don't. Some schools let kids organize in dorms by interest areas - for example, my son's college had interest groups (taking a floor or a wing of a dorm) based on international relations, environment, and so on. I think your best bet is to have her figure out which school she wants, and then go from there.
I'm not sure what you mean by "private" - do you mean isolated in a quieter area of campus, or less of a party zone (see if there's a substance free dorm), or with smaller rooms (freshmen will definitely get those!), or with private baths (hardly ever). All of the rooms will have the standard issue beds & mattresses if that's what you mean by comfortable. They'll get a dresser, a closet and a desk - and that's it. Suites with small living rooms are available on some campuses but often go to upperclass students. My son had a kitchen & living room for his last 2 years, and was in a modular apartment (campus owned but farther away) in his sophomore year. But that's entirely a school-by-school thing.
Best info will come from the Residential Life office (or whatever they call it) but it's all going to be in play until she is accepted and, most likely, enrolls. If you haven't taken a tour of these campuses, do so, and ask those questions on the tour (generally given by a trained student who will give you the scripted response but also his/her real opinions).