The PM has also not sent them the rent money from the past 3 months.

A line of credit won’t commit you to a monthly payment unless you use the money, so you can avoid paying interest when it’s not in use.

I’m thinking about selling it but wanted to hear your perspective, especially since the interest rate is so low at 4.75% & I don’t necessarily like the idea of selling an investment property but know my money could potentially be better elsewhere.

Something I do with my wife is quarterly money dates.

Don't reinvent the wheel, flip where others have made money flipping.

Clear out that line of credit and finish the apartment and move on to flips and try to focus on short term money and my business because I already have a couple of rentals set up for long term wealth.

With the money from my savings and stocks I have about 100k . 

Definitely invest some time and money in a decent photoshoot.

The developer makes their money on a one time developer fee of 10% of the total project cost.  

Once renewal period comes up (if they've been paying on time and causing no trouble) you can decide if you want to keep them or move on.