Swithching HDD with Modded/Unmodded Systems for Achievements

[Mr.]

I know that this question has been answered here before, but I wanted to be sure that nothing has happened recently in regards to this area. I have two systems, a modded system to play backup games (original Xbox 360) and another unmodded Xbox 360 slim. I have an adapter to use my hard drive between both of the systems. So I am wondering if I can play a backup game on the flashed console (offline of course) and gain achievements and then take the hard drive and put it back into the Xbox 360 slim console and go online and get the achievements downloaded to my account.

I also have another question. When the new dashboard update comes out will I still be able to go through this process or will I have to reflash another system that has already been updated to the new dashboard system. I'm just wondering this because I'm guessing that I would have to hook up my flashed system to live in order to get the new dashboard to play the games off the same HDD and the system would most likely get flagged/banned if I download the new dashboard update onto it.

I know this is a lot, so all help is appreciated!

[JAWS]

So I am wondering if I can play a backup game on the flashed console (offline of course) and gain achievements and then take the hard drive and put it back into the Xbox 360 slim console and go online and get the achievements downloaded to my account.

Yes. It's totally safe.

When the new dashboard update comes out will I still be able to go through this process or will I have to reflash another system that has already been updated to the new dashboard system. I'm just wondering this because I'm guessing that I would have to hook up my flashed system to live in order to get the new dashboard to play the games off the same HDD and the system would most likely get flagged/banned if I download the new dashboard update onto it.

Yes, you'll be able to still be able to switch your HDD between consoles.

Sometime after the 30th, M$ will put a link to download the update on their website to a CD/DVD/USB Drive and install it to your Xbox.