Just tryin to follow this long thread is making me dizzy

Here's what I've got going on with a UCD3D. I was first going to put a 61FX in it but after asking and reading here on RCU that the 61 will fly it with little power to spare.
I went down to my LHS and picked up a SAITO 100 for some better power, It looks to me that the Saito carb placement won't have a fuel siphon problem.

So now that I have the Saito 100 engine a couple more questions:

1) best if mounted inverted ?

2) should engine thrust angle be set right with a (2) washers under left side of engine mount ?

3) what pitch prop is best for the Saito 100

4) is the stock fuel tank large enough for the engine ?

More questions to follow

Bob