H1b application, help wanted

Company lawyer sent out my application for h1b on thursday night. The package arrived at Texas Service Center on Friday. Lawyer said he had the UPS receipt.

My questions are:
1. Does that mean my application is filed?
2. If yes, does that mean I am in the pending status now, or I have to wait till the receipt comes?
3. If no, will my application be returned if Friday is the cutoff day?
4. How long does it take for USCIS to open the package and send out the receipt?

I've been trying to find out the answers but had no success. Your kind help is greatly appreciated!