From what I keep hearing the Dallas TX market is very difficult for buyers right now.

I just never had this combo all in one situation before so its a little difficult to process.

The better quality ones are extremely durable and sometimes difficult to distinguish from wood.  

I personally wouldn't risk my money out that way, but it's all about balancing risk and reward and what you are comfortable with!

So can use that as your "land" portion, and the balance of your purchase price as your depreciable building value. 

If you're trying to wholesale without the first seller knowing about your buyer, you may find that difficult. 

This have been difficult for me because I have not yet done a transaction, I’ve sold some homes as a Realtor, but I feel like with how appreciated our market is, the price I would pay for the 4 units would be higher than the rent (unless new paint, carpet, and appliances were added - then I could increase the rent)...my biggest area of difficulty though is the MATH.

Sounds like if the eviction process becomes more costly and difficult, that would wipe out any positive benefit from collecting the option fee or having increased rents or whatever.

Prices are sky high and it seems like buying at these levels would not produce much extra cash flow.2) How difficult is it to invest out of state? 

Typically most performing notes I would expect to sell at 70-85% of the unpaid balance.4.