Like residential tenants, commercial tenants don't want a big increase in their rent.

The one specific one sits 40% vacant and we will be adding additional tenants to increase income.

But taking my willingness to move on as weakness and incrementally increasing the bill amount unreasonably.So, I want to prepare myself for all eventualities.

If not considering a 1031, there is a small capital gain, already taking into consideration $250k (single tax payer) if I prorate the 1031 portion, does it mean that the capital gain will be higher if I prorate the rental portion?

There is no other investment vehicle that increases net worth and throws off cash quite like real estate. 

You could also simply give notice that at the end of their lease the rent will be increased by $1,000, which would probably have them move out anyway at the end of their lease.

Student housing is probably still a sound investment, just don’t expect the dramatic increases seen last year in students from India to happen every year. 

I know how buying a house for a primary residence can become an emotional decision which increases the amount a person is willing to pay... but with attempting to pick up a long-term buy and hold, at least in my experience, the profitably is largely determined at purchase (and of course subsequent to this, proper tenant screening and management of the property).

Therefore for apartments you want to strive for buying ones that you know you can increase the NOI of after you buy it (forced appreciation).

We are going to see less and less 0% interest options and more and more increases in interest rates.