Alternatively, you could buy an apartment building with a lower deposit and reach your goal even quicker.

If you go this route, I would focus on a single property - the one which is costing you the most in interest and/or the one which will yield the biggest free cash flow once paid down - until you reach any prepayment limits imposed by your financing terms.Additionally, if you are able to switch your payments to {accelerated} bi-weekly (26-payments a year) from monthly, that alone will trim your amortization and total cost of borrowing.Another thing I frequently do is to take-on variable rate financing on a property (which is usually at a lower interest rate than a fixed rate loan ... by as much as a 1 pt), but set my payment as though I have a fixed rate loan.  

Because banks will typically loan 80% of purchase price or 80% of appraisal whichever is lower.  

Hello, I am interested in buying a small single family house in a decent neighborhood (average median house price around 450k), but the seller would want to sell the land (50x100) next to it together for an extra 100k to make a deal. hypothetically I can negotiate it a lower price for the land (any suggestion on how to determine the value for the land), what kind of investment can I make to turn the land into something profitable rather than just being wasted?

Sorry if I spoil your secret William, “Minimizing your tenants rent without lowering your income” is better known as “Section 8”

For example, you want to know if the seller has been doing snow removal for the past winter because one tenant broke his leg, even though snow removal was the tenants' sole responsibility.What issues, if any, have you had with the current and past tenants?

Also look at the investment as a place you can safely put cash down and know it will be their if you ever need to exit with a higher return than putting it in a lower yielding investment.  

Pods are rented for $275 which is $75-$150 lower then larger parks within 2-3 miles that are in a nicer park.

We wanted to rent it out on the lower end of the rental market to have constant renters and then the pick of who we would want to rent to. 

Whereas Investors, because they'd be putting down higher deposits and having worse Loan terms, may well be be happy with fully occupied homes (dependent on ROI).More often though, I read of Investors putting in lower offers for homes that are occupied!