LoneWolf

Focus works fine.  A power doesn't have to come from the focus for you to get the limitation for it.
 
Dumbo's feather is a great example of a focus that doesn't actually contain the power.  He needs it to fly, so it's a focus.  It doesn't matter that it's all in his head -- that's just the justification for when he wants to buy off the limitation after getting some more XP.

Another way to do it would be to use a PRE attack.  You would get a bonus for appropriate use of any interaction skills you make.  This would allow any character to try, but those with good PRE and appropriate skills have a much easier time.    

The best way to buy this is to purchase an NND attack.   2d6 NND, Continuous (30 active points).  This way you don’t take the penalties for performing the maneuver.  You also don’t have to worry about maintaining the hold, or the person being able to escape the hold.  You make the attack which goes against his ranged DCV so you are more likely to hit.  Once you hit the target takes damage, and cannot escape until you release them.  They can move but still take damage.

What does the STR min. have to do with a disarm? I would assume that a person wielding the weapon has the STR min.  The STR min has two effects.  The first is that if you do not have at least the listed STR you take a penalty on your OCV and DCV.  The second is what STR is required to add damage to the attack. 
 
Even if they do not meet the STR min they can still use their full STR in a disarm or other maneuvers.  Say I have 7 STR and I am using a great sword, my penalty to OCV and DCV will be -2 because I am 10 under the STR min.  When I disarm someone I take -2 to my OCV and DCV, plus any additional penalty for the maneuver usually -2 OCV for a disarm.  I can then use my 7 STR to attempt to disarm my opponent. 

It really depends on the campaign and the players.  Many of the people I game with myself included are in technical position, so some of the science ends up being very realistic.   But there are still players who are not as technologically sophisticated and often they are the ones who end up playing the more scientific characters.  This often leads to the person learning a lot about what their character knows, but they do not. 
 
On a couple of occasions we had game sessions that were almost completely technical in nature with almost no actual combat.  Having to investigate the security measures and find way to neutralize them was actually a lot of fun.