Being new to tax liens, I fear that I would be stuck with these lots if they don't redeem and I wouldn't have the marketing power to sell them. 

@Sean Riha Never let fear chase you away from your dream.

I am anxious to get started NOW rather than later because of internal fears of if I don't do anything now, will I ever do anything ever.

Opportunities knock every day.. most of us fail to hear it or fear to grab it (and yes, I have been one of those for many years).

To alleviate some of your fears about renting.  1st thing is you don't get as many midnight calls as youv'e probably heard.  

Although one of my properties is a 1950s build (had extensive plumbing repairs), I have been fearful of buying older homes for a few reasons - cast iron plumbing, old wiring FP panel, older building codes etc. 

Would you turn it down from fear of my walking away? 

Which is my biggest fear of entering this market.

This certainly confirms my fears regarding the situation. 

I'd be nervous about taking on that kind of project for fear that it will take a while to find a buyer with that kind of $$$.