If you have scheduled a service at the property to address a tenant's repair request its hard for them to complain or deny access.The exterminator's first visit may have been an "emergency" visit, but since you mentioned the exterminator returning every few days those follow ups are known well in advance and you can provide appropriate notice.P.S. may not be worth getting into this, but from what you posted it sounds like the tenants caused the problem.

I just read about some case law where a tenant screening company sued the courts because it was denied access to UD filings and they didn't prevail.

and how would you explain and deny the other ?

I would assume for future tenants I can screen for and can deny housing because of this.

Do you agree the following are good reasons to deny tenant applicant(within the previous 1.5 years)?

Sure doesn't seem easy now that the insurance company is cancelling all of the policies (and they denied all the claims but one) at renewal.

That way I don't have to worry about a higher debt-to-income ratio that would potentially deny me a mortgage in the amount I may need for my personal home property??

Not surprisingly, the tennant demanded his security back asap, to which I denied , stating that the lease clearly states the condition of the house must be broom cleaned, with no major damages.  

I don't really have any experience or really any knowledge about the mortgage process because I have only been in rental apartments when I was in college and when I did try to get pre approved for a mortgage I was denied due to the fact I have student loans and my debt to income ratio was to high.

They will receive the notice from the board in the mail.2) You may if you wish send a notice to inspect, this would also be a good opportunity to speak in person with the wife.3) You only need to use the address of the rental unit.4) If you file the L9 you may get a hearing this month or possibly next month, it depends on when they schedule hearings in your area.If you send a N4 the likely hood is that the board will rule that the N4/L1 will have caused confusion to the tenant and may deny the L1 and the L9 applications.