Other "products" (i.e. student apartments) that are farther away will always have better amenities than I will, however location seems to be the primary factor for the students.

The areas you specifically mentioned have seen growth due to those factors (Buckeye - industrial expansion; Surprise - TSMC plant relocated). 

If you're looking to invest in Jerome Village, definitely factor this future charge into your cash flow calculations and maybe have your CPA take a look at the exact language in the Declaration. 

If you're comfortable with these factors and the cash flow remains strong, it could still be a great opportunity.

Can you show reserves factoring the DP and closing costs?

Did we factor in for these adjustments and what will come of cost should we transition to a hold strategy at (x) less $s or (x) more $.

Just remember to factor in that you will now have fixed monthly payments on the original three which will reduce your cash flow.

This could mean investing in property flips or purchasing out-of-state rentals for more stable income, but it would require letting go of the $1,350 rental income from the manufactured home.What factors should I consider for each option, and how would an experienced investor assess this situation mathematically?

The first is the way dividends or rent is payed is through tokens which recently have been under pressure due to their transaction cost, it's not a deal breaker but it is something that factors in when you go to turn your tokens into money.

Keep in mind though that your return on equity on your 400k equity goes from 1.5% right now (assuming 500/mo positive cash flow) to getting a -3% on the remaining 200k in equity, so that is also a factor.