They must keep track of all invoices to be charged towards the security deposit outside the scope of normal wear and tear.

Is it normally, the higher the chance of clash flow, the lower the chance of appreciation?

If you piss them off, ypu might then have a nonpaying tenant with no way to remove them.Id deal with it til things are back to normal then deal with it then.

Even now, with the doom and gloom in the headlines, we are still technically in a seller's market with supply far below normal.

We normally do open houses.

I assume you could still qualify for a 150k fourplex with a normal job.

I charge a refundable deposit equal to one month of rent and I charge a mandatory cleaning fee of $100 per bedroom and bathroom ($500 on a 3bed/2bath).I have a company right now that is paying $2,200 a month for a single-family home that normally would rent for $1,200.

I'd mostly use these ideas in other cities that I don't work in, going through normal channels.

This depends on your personal investment philosophy and/or what gurus you follow.For example, many in the FI community would say you should not mix your 401k (normally equities investments) with real estate investments because the diversification you get by investing in the equities market and the real estate market are a boon. 

I understand that but when I’m being charged 150$ for each question is that normal?