Sadras
Legend
Furthermore, while we can modify...and we can also use 3rd party mods...I think we can all agree that it's better if a game has fewer flaws in the first place that don't need to be rectified afterwards. I can think up new options for a monster, but I'd much rather have options that are the result of hard work and creativity from a team of designers and an even larger team of playtesters.
The rest of your post has some ideas, some of which are pretty good, but surely you can understand that it would be better if ideas like that were in the monster manual so that DMs wouldn't have to track stuff like that down in random posts on 3rd party websites (in threads with titles that seem to have nothing to do with improving monsters)?
...(snip)...
While new mechanics would be welcome for the monsters, it would be nice simply having a paragraph with each entry that makes some suggestions for how that monsters might behave in unique and interest ways. E.g. turn the fluff into...not exactly mechanics, but strategy (or lack thereof). Some tips for the DM on how to make the monsters come to life a bit.
Fair enough. To be honest, whenever I introduce a new monster into the campaign, I usually research the previous editions MM (monstrous compendium for 2e) to mine for inspiration for possible additional mechanics and roleplaying ideas. Although I love the 5e MM, I still find myself doing that, in case I miss something or do not play something true. I'm a mental case that way.