Leaks are pretty unlikely from a laugh or cough. But you have to be careful not to lift anything heavy for approx. 4-6 weeks (my limitation was 10lbs, then 20lbs). It will be sore and you will know when to "baby" it. The hospital that I had surgery at gives all bariatric patients a "Bari-Bear" and it helps when you sneeze or cough to hold it close to your abdomen. You can do the same thing with a pillow.
Scar tissue can always pose a risk, but that's what pre op testing is for. It should only cause a problem for future surgeries. There is always the possibility of a stricture as well. But they are easily identified and treated.
You don't need to practice sipping, your body will remind you, that I promise. Some people don't have a problem with drinking after a few days, weeks, and some take months. But within a few weeks, I could gulp without a problem. The bigger concern is the frequency that you are drinking. Make sure you set a timer and get your fluids in.
One of my top ten tips, is to avoid protein shakes until you have to (pre op diet or after surgery) because those shakes will become your worst enemy eventually. No need to expedite the process.
Crushed ice should be OK after surgery. I know a lot of community members who actually make snow cone ice and its been a God sent for them.
Good luck my dear! Congrats