So my caster is up to his dice stacking "Quickening" tricks again.

1) Can it be used on anything not matter how simple it is? Like a Hammer?

2) His goal is to:

use Analyze Device to add 6 more dice when firing a gun.

I personally feel its ok to do this but he should use this or the skill which applies, which ever is higher.

But it doesn't say this in the book.

any thoughts?

Let him do it. He's got all the downsides of the reasonably powerful Quickened spell to deal with. Have magical security bother the team when the go into the next secure location because the glow moss security system installed in the door frames with photosensitive sensors to determine when potential magical threats enter the building alter the building's security, or something. Nothing for free, but his use of the spell is reasonably valid as long as you consider a gun a device. You could say that only smart guns can be analyzed, but then he'll just get one of those if he doesn't have one already.

Also, I wouldn't enforce the skill or bonus dice, whichever is higher. The spell specifically allows for bonus dice when using a device, so that's what he should be able to get.