You are at 72% LTV - you can roll up to 80% LTV in the loan for closing costs - maybe its the case you have to come out of pocket a bit on closing costs.

Acquiring pre-existing rental portfolios?

My goal is to try and get a multifamily property a month or two after starting my job once I have the paychecks rolling in, to show my financial advisor.

Make sure to research lenders, get pre-approved, and calculate your potential ROI before bidding. 

Hope is the industry gets some relief soon and I can revisit some options to further improve asset revenue through amenities and/or roll into a better rate a lower principle.

So if you discount a small amount to get rolling, that is something that can work, but don't want to stay low for long.You will start to get the dregs staying at your place and they can do some real damage to the place.

Once converted to a rental, repairs and improvements may qualify as deductible expenses, but pre-conversion repairs typically do not.

If you identify a problem, ask the seller if it was pre-existing or caused by the current tenant.

NEVER borrow from a 401K, you are taking pre-taxed dollars and paying it back with after tax dollars, you do not get to return the loan with pre taxed dollars, in addition, some 401K plans do charge interest and maybe even fees, and lastly if you get laid off for some reason, it is a distribution with all the "fun consequences: tax at the last dollar rate, and if you are under 59.5 there is also the additional 10% penalty.Personally I like the HELOC, however you can also sell stocks and do tax harvesting there to offset gains if that is an option

My retirement system doesn't allow for me to roll anything over given that I'm still employed with the company and also under 59.5 years old.