Agent Skills for newbies

I recently started exploring Agent Skills. While I find the concept genuinely useful, there are three questions immideately coming up my mind:

1) How to avoid bloating of .agents/skills with "may be useful one day" files?

The nature of skills would tempt me to make a large collection relevant to project tech stack. But each skill can be accompanied by tens if not hundreds of associated resources and additional files.

How to decide what can be really useful and what is not?

2) How to keep downloaded skill files up-to-date?

One wouldn't like to re-invent the wheel. For common tasks there is probably someone out there who already wrote better skill than I can. At least in JS ecosystem - which is my primary domain right now - I can use skills package to "install" various skills on your machine. And if not this, I would download them manually.

But what if the source changes because things keep evolving? How to manage the local state easily? I don't think I want to manually go through and check for updates...

3) How to make it portable between projects/devices?

Eventually, I will put together great set of skills. But then I start a new project. Or move to another device. How to take the .agents/skills folder with me? Put everything into Git repo? Or have a Gist with list of skills to install?

I am quite sure I am not the first one asking. Are there concepts and tools to make this easier yet?

What is your experience and what advices do you have?