Jose - I think you're doing well at understanding and listing the problems, which means finding solutions is a good next step. Here's my contribution to the solutions step after having seen the problems which you now mention years ago...
Reading back to my earlier post where I mentioned the Keynote Manager+ as the app that's been my solution to Revit's keynote deficiency, I failed to mention that KM+ now has a feature where the keynote database (.txt file) is stored in a central place (cloud) via Amazon's servers. This means that once you buy KM+ cloud licenses and you create a KM+ "project", the account admin can distribute permissions amongst all the users on the company's cloud (because the KM+ cloud setup assumes a company essentially having a cloud to itself) so that employees with internet can be anywhere in the world and operate out of the same keynote file.
Even works with C4R licenses. I know because every Revit user at my firm has C4R capabilities and each has a cloud subscription to KM+. They live with both, daily. I can login to a model if I travel and view, use, and edit the same keynotes everyone else on the team is using.
Also, and one of the best features of all, is the ability to have the entire team of worker bees creating, organizing or editing a keynote database and have that work continue to be there for future projects. I've done this through my use of a single KM+ "project" throughout all projects. Don't think that the app author intended it to work that way, hence him calling a single cloud-based keynote file a "KM+ project" but it works as I've described, regardless. I have everyone on my team login to, open and constantly add to a KM+ project called "Company X Keynote Master Project". Every C4R shared Revit file, now and in the future, will point to this KM+ project aka cloud-hosted keynote database. Because my team knows the naming and organizing standards I've developed over the past 4 years, what I have now is a beast of a database of terms. Don't have a keynote for 3/4" GWB? Add it. It will always be there for everyone for all time. Every project we do I can feel myself saving time. Feels great.
Must sound like I have stock in the KM+ product by now but rest assured, I'm just an idiot consumer like anyone. There might even be another developer who can kick their ass in terms of features. Don't know. Haven't researched intensely in a few years.
So here's a recommendation from being where you were in 2014. Find a cloud-based app and service, purchase licenses, download the app, setup a keynote cloud and then get your life back. You don't even have to use Revolution Design's (KM+ author) app but you do need to get into a cloud-based keynote management workflow. Otherwise, have fun with text boxes ![]()
Best of luck.