I don't want to sound overly mean, but at the same time, I don't want to sound soft either. That really is just your experience, and it's known that some landlords will pull an applicant's credit report.

In general, places with higher turnover don't because even if you have a defaulting tenant (as a credit report would hopefully prevent), you can get a new one with less issue. In less populated locations, you'll often get hard inquiries.

In my opinion, no, a single inquiry won't really matter. This will vary depending on the banks, but, that's my general feeling.

As a first issue, though, you should try to avoid getting a hard inquiry in the first place. Find your desired living situations and then ask the landlord if a hard inquiry is performed. If it is, then ask if you can avoid it by providing proof of your credit worthiness. If they ask why, legitimately tell them that you know of the potential impact of a hard inquiry and would like to keep your credit in good shape.

Personally, I've taken the automatic shotgun approach. Somewhat large app-o-ramas punctuated by fairly short resting periods. The worst of both worlds, and I'm in decent shape in terms of approval. I'm not going to deny the effect that inquiries have, but the amount of hard inquiries you have is only one portion of your credit report, which is only one factor of your overall credit card application (which includes such things as income).