Unexpected repair gets done right and an extended vacancy isn't that stressful.i guess my answer is I have no number, or if I do it's fluid based on my lifestyle.

How to do you guard yourself against getting too excited and over extending yourself or making those bad decisions?

Most of them also wanted extended closings (up to a year)  I was ok with about 6 months since I needed that time to make my new SFR home habitable before moving there.I also did enough digging to come up with the mailing address for the LLC that had bought the property across from mine at $740K. 

This way another buyer comes along they have the choice to match the similar or better offer otherwise they lose the chance to buy the property.Additionally have earnest money held by an independent party with the transaction and have built in escalators for more and more non-refundable money each time they go to extend the contract.

Pest control, even when it's bad, is very fixable with a decent extermination and a lot of understanding extended to the tenant. 

Now I’ve asked the seller to extend the closing date and they accepted 7 more days for us to have the lender’s underwriter to review the appraised value.

Give the tenant the appropriate notice and then bump it.I don't recommend extended notices or graduated increases.

According to VA, you have 60 days to move in, without a “valid reason” to extend.

I guess I can also make the argument that any damage that wasn't there when the tenant moved in is game for deducting from the deposit.Finally, can I refuse to spray for pests if the property isn't kept clean and the doors are just left wide open for extended periods of time?

Due to unforeseen circumstances discovered by the lender, I as the buyer had to ask the sellers to extend our closing date to the following week from 11/15 to 11/22.