To be clear, it is totally ok to APPLY for more than one (shopping rates/lenders/brokers) however having multiple loans going at once (if you were doing a loan for your primary and one for a rental at the same time) requires disclosing on the application that you are getting another loan while your current loan is processing.  

Loved* That Respose     What is another Software you recommend, free/paid?

FULL-SERVICE OPTIONA servicer offering their full services usually charges from $75 - $150 per loan per month (pricing is usually different for non-performing and performing loans) and performs the following tasks:Boarding of your loans – The servicer will enter all the necessary information about your loan into their loan management software.

When a vacancy comes up in a good apartment on SFO, operators often have literally hundreds of extremely well qualified applicants at incredible rates.

Keep in mind you cannot discriminate Section 8 applications. 

Anyone have tips on the best all in one self management software?

Since we don't have our primary yet, I feel like it doesn't make a ton of sense to get into buying rental properties and potentially hurting my own mortgage loan application.

If you're using RentRedi as a managing software you can add Latchel as a maintenance service.

This period of Short-TermRental Operation shall be specified by the property owner in the required LakeGeneva Short-Term Rental Application.

Here is some free advice (worth what you pay for it):Upon application, obtain a handwritten statement from the borrower describing the intended use of the money.