Gmod acting up.

I recently got back into Gmod. Suffice to say it was all older stuff from the grand Gmod 12 days, so a full sweep was necessary. I’m aware of the multitude of bugs now present due to the switch, but the ones I’m specifically having issues with haven’t really been mentioned anywhere, which leaves me with a few questions…

1)Garry closed an issue concerning the Paint sTool on github, remarking that it simply “doesn’t work on world”. Does this mean it’s been left in the current state for the time being, or is this (hard to believe) final?
2)Material sTool is acting up. Sometimes it paints the material on props/players, sometimes does it only ONCE, sometimes doesn’t work at all, and seems to NEVER revert them.
3)Effects tend not to play. For example, blowing up a number of barrels from further away is heard and seen, but the debris+effects are not. Once I close in to about 10 meters or so do the particles and effects play, and cut out again when I increase distance. My console often repeats something about an effect called dusty.rocket.explosion or something along those lines (will provide actual console feed if necessary).
4)Props tend to disappear. As simple as that, they become invisible, but remain interactive. The only way to tell where something is is by global shadows (which have also gone ninja on me at times…).

The general feeling is that of Gmod simply falling apart right under my nose. Any tips?