cashflow vs. payment of principal

[Joe Smith]

I'm considering delving into small multifamily or mobile home parks (for rental/cashflow) in the $500k - $1.2M price range.

My questions:

1. Since commercial financing consists entirely of balloon loans from what I can see, is there ever really an "end game" of having a paid off loan someday and retiring on the cashflow?

2. Assuming it cashflowed well enough to do so, would there be any financial reason to attempt a faster paydown of principal?

3. Are commercial loan prepayment penalties of the type that kick in with the first extra dollar of principal paid, or does it have to be 20% or so of the loan amount before it comes into effect?

Normally, I'd have no issue with the idea of just refinancing at the end of the balloon, but after this last lending fiasco where we *almost* reached a point that commercial financing was just not available (it's still tougher than it was), I fear being unable to obtain loans and losing everything at that point.

I still work a "day job" and plan to continue to do so for at least another 10 - 15 years, but, at 31, it would be nice to be able to retire by, say, 50 and live off incoming rental cash flow.