US Immigration from Kenya

So I finally submitted my i129F application yesterday for my k1 visa and I would like to know what to expect now? How long does it take before you get the notification that the application has been received? Does it usually take several weeks or does it only take a few days?

I have the Lewisville, TX USCIS address listed on all of my statements included with my i129F. However, they're all going to be inside the envelope that I send the application in (meaning the reviewer won't see it until the envelope is opened). And at the last minute I decided to use the address for regular USPS shipping (which is the Dallas, TX address), as the address that is on the label on the envelope. Will this inconsistency be an issue and risk my application getting denied or is it not a big deal?

On the credit card payment form, the G1450, it says "Do not submit this form to a USCIS field office. They will not accept it." And I wanted to know what address is the "field address" and what address is the lockbox (the location that they *will* accept the g1450 credit card payment form). From looking online there are two addresses that it could be sent to: the Dallas, Texas address, and the Lewisville, Texas address. (Note: I'm in the US filing for my fiancee in Kenya).

Can you pay the fee for the k1 visa online? I'm a US citizen filing for my foreign fiancee. If payment online an option or does it need to be a check?

Checked my DS 260 confirmation page it doesn't have a pic. Is that how it usually is? just curious coz the non immigrant had a photo of application.

Or am I using an outdated pdf ?