It's too early and insufficient information to make any judgments on this new shotgun. The article indicated that it is still in the testing phase, so, many changes are possible until it is perfected. As far as rails being inside the frame connected to a vertical foregrip outside (regarding the grip breaking and losing the ability to operate the action), the Steyr Aug also has an external charging handle attached to the internal bolt carrier. Under your theory, if the charging handle broke, then the Steyr Aug would be nothing more than a useless club. I've owned and operated Steyr Augs for almost 20 years and the charging handle, or any other part for that matter, has not failed. And, the charging handle on the Steyr Aug is a lot smaller than the foregrip on this shotgun. I'd just relax and wait for this shotgun to complete the testing phase and see what is finally released.
Don't know how complicated it is to disassemble. Probably disassembles in a manner similar to the Aug, which is not difficult. You want difficult to disassemble/re-assemble? Try the KelTec RFB. That was a lot of fun to take apart to clean. Not!