I am in process of setting up bank accounts for each and transferring title from my name to LLC.

Again, you may run into transfer limits with some of those other apps which aren't necessarily designed for the purpose of rent collection but the right landlord software can make this seamless for you.

They’re also free and they transfer the money much quicker than Cozy.

Is it recommended that i have the company transfer the warranty deeds in my name or my LLC's?

Most likely, no one is paying the tax bill, but someone has been purchasing the tax liens and it will eventually be transferred to the tax lien holder.

I have read that you should have an attorney look over your contract before you present it to the seller, as well as have a title company transfer the title after you come to an agreement with the seller. 

I called documents company and they said they charge $100 to transfer the property's deed to me.

@Kenton McDanielIf there are federal tax liens a deed in lieu will not work as the default won’t allow the title transfer at no cost if the house has equity.

Germain Depository Institutions act of 1982 forbids banks from triggering the due on sale clause for transfers to an inter vivos trust. 

The 1031 company only transferred my name onto the new properties and not my partner (we should have caught this but we didn't until it was already done).