Intrigued, I emailed back and it was some legitimate agent from a well known RE company that represents "investors."

Best bet IMO is find an actual and legitimate GC - one that uses ironclad contracts and will throughly qualify and take responsibility for all subs - thats what his fee is for, he is a general contractor, contractor being the key word.  

I'm looking for reasons someone might justify a lower offer, or if not, why the asking price is legitimate.

I have a legitimate reason for imposing limits (water/septic) but I have hesitated to do so when advertising.

On that note I also source investment properties so in case this property does not plan out I can be another venue to acquire properties. 

If there is a phone number, or googling their email gets legitimate results, it could be legit.

My attorney told me a tenant cannot legally withhold rent for maintenance issue, legitimate or otherwise.

There is quite a number of threads about this with various opinions and suggestions.I generally don't have an issue with giving out my account number (for legitimate reasons), not sure why people are super secretive about it.I don't see a real risk especially nowadays where you can watch your account online any minute plus with all the liability protections offered.Some services you don't have to give out your bank info to the tenant, too.And no, no reason to not do auto-pay, expect you don't want to to suck up a $3 fee or so (depending on the service chose).

Can you really get a legitimate license from online classes compared to classroom courses?

It's difficult to find a legitimate, good pm co.