even if its interest only, id want to pay down principal here and there. seems like sellers would offer this interest only route so they have 0 capital gains tax, but id rather pay down a bit of principal in 7yrs. i see its not required but it should allow for principal paydown in promissary note3) any general advice to look out for on seller financing?

Typically starting with a smaller rehab budget of $50K or less (maybe a max of $75K) and avoiding a 1 to 1(or higher) ratio of purchase to rehab costs is recommend when you are first starting out. 

In some instances the estimate may be less important but rarely if ever do I not see a requirement for no appraisal unless the value is 4x the loan amount.

Highly recommend.

BiggerPockets also has a calculator to analyze deals, and I highly recommend you start this as soon as possible, even if you are not ready to buy.

(ii) Can anyone recommend an agent in the Philadelphia area who specializes in apartment buildings? 

Can anyone recommend an eviction attorney with reasonable rates? 

.- If you decide to have an LLC for each property, creating a Management LLC that all the other LLCs "hire" to run their books, will allow you to only require a bank accont for the Management LLC.2) You may not be able to do a Trust.

I own a 17 unit apartment building near Minneapolis built in the 60s and wanting to implement wifi camera system and modernize the access panel (wifi managed).Any vendor recommendations?

Will the title company put this property under our LLC name, and won’t be required to legally inform HUD/tax authorities. - will it influence property taxes once we move to conventional loan in 3 yrs?