The term "shady manager", in my opinion, is withholding pertinent information or being misleading in order to lock owners in to a contract and then take advantage of them. 

I just withhold the taxes to make sure they get paid.

If not then you may be subject to FIRPTA withholding which is 15% of the sales price of your relinquished property.  

it would be tough to go into the winter with holding costs when that may have ultimately yielded the best net.

That keeps him from withholding rent and sending you down the path of just use my security deposit for last month's rent. 

Potential applicants , assuming they are serious, withhold nothing.PS: A potential bad tenant will infill your interview questions with additional useless information to distract you and redirect the interview, they are often sickeningly sweet, offer to do work for free, rave about how great they think the place is, brag about there gardening abilities etc. 

They stated they waited several days before telling me and this has been a ongoing situation for 6 months and they had to evacuate the property due to feeling sick and it being unsafe and they are legally allowed to withhold rent from me.

W2s are issued by your employer at the end of every year -- they summarize your earnings and tax withholdings for the previous year of your employment.

If he makes the loan directly (i.e. personally) from Canada, there will be a withholding tax by the IRS on income earned.

If you withhold information on a 1003 Loan Application it is fraud by deceit (a lie) and actually a Federal Crime.