You can practice with a group as many times as you like. Very likely if you need practice on T9, you have overcome the other turns and have that week to do it. If you don't have the time to practice that week, then please look forward to the next patch.
Loot lockouts do not solve the entire server beating it much...much faster if it was a thing and then people complaining about they have nothing to do till the next Coils hits. There is suppose to be content that not everyone can beat at it's prime, that is the intention of the design and from I see, it is working pretty well. I would hate seeing people walking around in High Allagan weapons if they did almost nothing to deserve it. Granted you can do that now if you are willing to leave your 8th member out that week, but most groups don't carry in someone. It would definitely be a thing however if they released the locks.