Nothing is more valuable than knowledge when applied properly.

If they haven't applied for assistance you may be ok https://homelinemn.org/phaseou...

Does the lease say anything about how payments are applied to existing balances?

After they are gone, apply the deposit to the unpaid rent, cleaning, and repairs, and then decide whether to go after them for any unpaid amounts or if you'll just let it go.

Can he file a quit claim deed to add me to his title and then I apply for a HELOC on the PA property so we can make improvements and buy an investment property?

Painters and other contractors are fully aware of lead paint used on older properties and know what not to do. 

For rent accruing on August 1, 2021,or thereafter, and unless an exception or other state law allows for eviction, landlords areprohibited from serving or enforcing, or threatening to serve or enforce, any notice requiringa tenant to vacate any dwelling, including but not limited to an eviction notice, notice to payor vacate, unlawful detainer summons or complaint, notice of termination of rental, or noticeto comply or vacate, if, unless otherwise permitted by this order or under state law, a tenanthas (1) made full payment of rent; or (2) made a partial payment of rent based on theirindividual economic circumstances as negotiated with the landlord; or (3) has a pendingapplication for rental assistance that has not been fully processed; or (4) resides in ajurisdiction in which the rental assistance program is anticipating receipt of additional rentalassistance resources but has not yet started their program or the rental assistance program isnot yet accepting new applications for assistance.o There is a presumption that any rent payment made on or after August 1, 2021, isapplied to current rent before applying toward arrears.o A landlord is not required to accept partial payment of rent but is required to offer atenant a reasonable repayment plan under this order and pursuant to Section 4 ofE2SSB 5160.o A rental assistance program is authorized to share the application status of a tenantwith the tenant’s landlord.https://www.governor.wa.gov/si...

Once all is agreed upon and signed between your team (you and your attorney) and their team (the seller and their attorney), You will then need to turn around those documents to the lender who will go through the process of qualifying you for the loan, applying for the loan and closing on the loan. 

I have applied for NJ assistance but I am not sure if i should wait for that money, as it has to go through lottery and stuff. 

I’m not sure if that would apply for you but I always recommend that to people.