You give however many warnings to neighbor A as your attorney advises, and then cancel the tenants lease and head for eviction if needs be.As for neighbor As hand, tell him straight that if his dog hadn't caused a fight, he wouldn't have had to break it up, and he wouldn't have got bitten.Personally speaking, my patience with dog owners who allow their dogs to get out of their yard is running real thin these days.

She has been keeping the apartment clean and there have been no more problems with others living there, so apparently my verbal warnings, about non-tenants who were seen living there, were sufficient for her to change that and comply with the lease.

I would give them a verbal warning to the same affect even if you don't have it in your lease.

Not only that they warn you when to take this seriously.

I would also do a unit inspection, there is no need to give a reason as long as you give them your states mandatory warning ahead of time.

Even if I'd warn the applicant that the place wasn't ready and that it was going to be painted, new carpet, whatever, and they'd insist that was no problem, they just wanted to get an idea of the space, etc., they inevitably would look worried about everything, and start pointing out unnecessary fixes that they thought should "also" be fixed.  

Auto accidents on premises are not a landlord liability matter, generally, I say generally because you can be found negligent if you fail to provide reasonable traffic notices, signs or warnings for drivers.

Occasionally stop by the tenant's home without warning, during the daytime only, and ring the doorbell/knock.

Now she's a tenant, and now you're in a position to have to watch her and give her warnings, and threaten to evict?  

Repeated or consistent late payment is usually justification for eviction.You need to get rid of this tenant as he is training you to be the worst kind of landlord.I would hope he ignores your warning, pays late, and you evict.