It will take some time to find a property that fits your buy box (price, rent to price ratio, etc).For primary property leases, you have a little leeway about when you move it. 

I have a downpayment saved, good credit, but do not own assets and my income is historically up and down due to commission checks from brokerageIm concerned that I’ll waste time looking for deals and making offers to ultimately not get financing - Should I be reaching out to lenders first to see an amount I would get approved for and then look at deals that fit?

A lot of this is going to be what fits best for you - your comfort level and your experience level. 

Considering how large the mortgage payment will be, it’s hard to envision finding a deal that really fits the criteria with FHA.

The XXX Rule is your “no.”What parameters can you put in place to help create a “no” for a deal, meeting request, or anything that is not the best fit for you and your limited resources?

That is a story fit for reality tv!

But it must fit your goals and often selling could be better.

Fitness places I also am no excited about.

Saw this in Facebook (from Amazon) ...Fluidmaster 7530P8 Universal Better Than Wax Toilet Seal, Wax-Free Toilet Bowl Gasket Fits Any DrainLooking for anyone who has tried such things and how the experience has been with it ...

There is definitely a box you have to fit in though.