No worries, @longmann - I've been here for over four years, and I still have questions. 😂
As far as I know, it's difficult to determine how much Hive Power/Resource Credits (the amount of one determines the other) you'd need to do a single post, since it depends on how much data (text, photos, etc) it contains. The HiveBlocks link I shared above is probably the best way to keep an eye on approximately how much activity you can do on chain each day (that section that reads, "Enough credits for approximately:")
And if I understand your second question correctly, you can only delegate Hive Power that you hold in your wallet. If someone delegates to you, you can't then delegate it to someone else. If that's not what you were asking, please feel free to shout out again, and I'll see if I can help you understand it. 😊