No, epoxy is generally not weak. That being said, epoxy putty sets like a rock (almost literally) and is much harder when set than straight epoxy glue is. It really depends on just how much stress a given connection will be put through. For micro screws I'd most likely use straight liquid epoxy, myself, but if you need either extra strength or need to rebuild something where liquid cannot be contained to do it then epoxy putty is the way to go. Just be aware that while most screws can self-tap into solidified liquid epoxy if a tiny starter poke is created by a needle for non-pointed ones, that's not the case for epoxy putty. You will have to drill set putty out with a guide hole for the screw.
Were I you, and if you're intending to do this sort of repair regularly, I would invest in a rotary tool (e.g. Dremel) with a flexible extension and chuck, and get some jeweler's drill bits (see here) so that you can either drill guide holes or use them to drill enough holes in the epoxy that it's easy to pick it out with a pick.
I don't think you're ever going to succeed with the snap tabs as far as gluing them is concerned, unless you have the space to build up a larger "base" around where you're gluing them with extra epoxy. There's just not enough surface area to create a bond that can withstand the shear that these things go through when in the process of being snapped into place.
I might undertake what you've undertaken for my personal amusement on a machine I wanted to keep for some reason, but if it were someone else's, and financial considerations are not a factor in keeping it, I'd definitely recommend a new machine and data transfer. It's more cost effective than the amount of an average tech's hourly charge to do the kind of work you describe if we're talking about more than one or two of the repairs you've mentioned.
Edited by britechguy, 13 November 2017 - 10:02 AM.
Brian AKA Bri the Tech Guy (website in my user profile) - Windows 10 Home, 64-Bit, Version 1803, Build 17134
. . . the presumption of innocence, while essential in the legal realm, does not mean the elimination of common sense outside it. The willing suspension of disbelief has its limits, or should.
~ Ruth Marcus, November 10, 2017, in Washington Post article, Bannon is right: It’s no coincidence The Post broke the Moore story