Well there are some mitigating factors to your paranoia on UFED
-- Cellebrite, the owner and developer company for UFED, only sells its product to governments and law enforcement agencies so any bootlegged copies someone does buy off of source like eBay will be unsupported and unlicensed. So simply because someone may actually buy the product, that doesn't mean they'll actually be able to use it. Possession doesn't automatically and magically add knowledge.
-- Of course it's a remote possibility someone (i.e. retired cop) who has worked with UFED in a work setting and knows how to use its various modules will buy a copy and go out in the world snapping up people's phones to extract data, but that's something that's more prevalent in TV shows and movies. Here in the real world if you're really so fearful there are people lurking around and waiting to get your phone, it's time to stop using it. Remove the SIM card and any microSD card, go into Settings >> Accounts menu and delete your Google account, then do a Factory Reset and destroy the phone with a hammer.
Personally I think you're being too apprehensive on this matter and should just ignore all the fear mongering in the news media and such. Yes there are some really moronic people all around us who have no problem using something like a bootlegged copy of UFED to exploit others, but their numbers are really minuscule. Just be sure to always have a lock screen enabled when you are out in public, don't leave it just sitting around unattended, and stop letting other people borrow it.