The concern about tape is about the opaque brown tape also used for taping boxes. I buy the clear 3M tape from Costco at a very good price. After the package is closed, I run three lengths of tape over the label avoiding overlapping much. The clear envelopes mentioned earlier are provided free by USPS for international paperwork. They may frown on their use for domestic packages, and the package may end up in the wrong bin.
The pickup needs to be scheduled separately from the label. The PayPal label service has a link to do that on USPS. You would do well to have a separate registered user with USPS for printing labels that can not be handled by PayPal and for scheduling pickups directly, ordering free supplies, stamps, etc. PayPal refuses to handle the Large Flat Rate box as well as the new small version. I make those right on USPS and use my PayPal debit card so the funds come out of the same pocket.
I leave my packages on a table at the front gate covered with a tarp. Whatever you do, meet your postal carrier and explain your business and agree on the best way to handle it. If you are a regular shipper, meet your postmaster as well. Note that you can put your regular outgoing mail with the package and it will get picked up as well.
My wife leaves refreshments for the carrier sometimes, and I even have his cell phone number. If I have a critical pickup or a last minute package, I give him a ring. Support him during food drives and recognize his value to your operation, and keep your dog away from him. I consider my postman a member of my team, and we remember him at Christmas too.
USPS is the only shipping service I use. UPS is constantly changing drivers, and they can't find their way out of bed in the morning.
Hope this helps . . .