It is good to have different keys although I do not find it easy to get access to them if needed.
To be honest I never used the memo key. At times it feels to me it is too much.

I also noticed that if (an app) tells you to sign in with the posting key the active is needed after all.

Keeping posting and wallet separated is a good thing. I wonder how many extras are needed. Most users will not understand it just like this article.

It's great to read you are enthusiastic about what you do.
🍀💕