I didn't know if I was wasting my time with the webinar's or not, and wanted to know if other people heard of it.

This year I just did my taxes on turbo tax because I feel like I could do better myself instead of wasting money to have my taxes done.

It sounds like you already renovated the 1/1 SFR so at this point razing it to build new would waste that reno cash. 

Tillman Fertitta the Billionaire in a video once mentioned he likes to load up on good debt when lenders are giving favorable terms and higher LTV's.His thought is that you save up as much cash  as possible because in a down turn lenders TIGHTEN on what they lend on and what percentage of LTV.

If you buy new do not waste your money on a extended warranty.

What is the best approach to prescreen tenants so that I don't waste my time and current tenants' time on someone who don't qualify? 

You could talk to an attorney but likely they tell you this would get very expensive and you just get a judgment that is worthless and waste big time and even more money chasing bad.

-The capital noted above would be spent, without the full load of traditional closing costs on homes that met certain mutually agreeable characteristics.

I'm not sure if that would be too aggressive (revealing that I'm a motivated buyer) but it's worth a shot if I want to move forward and not waste time...

I do not waste time with offer dates and multiple rounds of bidding requested by the seller.