Don’t want to spook the seller off.

So I thought the seller might be spooked with that happening again and used the higher earnest money and quick close to get them to see I was positive I could close. 

I don't want to spook the owner.

As the transition happened very quickly for these tenants (and all were very much spooked) we gave him a 1-month grace period / allowing him to pay on the 10th that first month and told him in no uncertain terms that the following month rent needs to be paid on the 1st and is late on the 5th. 

I was hoping to hear how risky it sounds to raise the rent to $550 and cover the water/sewage bill myself without spooking off my current tenants.

Be careful how you talk with your new tenants, as this incident could spook them and they may decide they don't want to move-in at all.I don't know what the loan department of the credit union will need to know.

If anything you'll spook them and welcome to turnover, lost rent, etc.

On more than one occasion it's been enough to spook me as a buyer.  

Tenants (for whatever reason) have a tendency to get spooked when there's new ownership.

And yes, you would think this would be the case, but foreign income either spooks some lenders, or perhaps they just don't know how to go about reporting it...As I lived abroad ALL of 2016, my income was not subject to US Tax at all (I'm within the cap guidelines and domicile requirements), but as I will be in the States from September on, I will owe regular US Tax on what I earned abroad (which stinks because I am already taxed here as well).