While there are still some properties that ca be profitable, other areas might be more desirable in this area.

Besides, I'm a newbie and many investors disapproved of this deal the last time I posted it at BP.A few days later, to save my friend from an unprofitable deal, I ask her to buy a house for herself since she's not into it for profit but to seek a bigger shelter than her condo.

and if renting for short-term is even profitable?

If you were thinking about moving back in so you could access the profit through the primary residence exclusion you'll only be able to prorate it between the times of "qualified use" (as primary) and "non qualified use" (as rental).  

Additionally, you will be surprised by the amount of heat a hot water tank generates in a small space. 

Would the seller want to partner with me : where I fix it and sell it and we split profits? 

Some of it is already invested, but I would like to get on track in real estate to start generating monthly income on the side in the range of $4000-$5000.

Sounds to me like your first move should be to sell your NJ rental and invest the proceeds somewhere more profitable.

I'd recommend keeping it simple, clear, and unemotional and enforce the lease or you will burn out or not make any profit.

I am looking at a park that is pretty awful, which too me is exciting because I see lots of potential to take this poorly maintained commercial property and polish it up for some killer profit.