Stupid questions from a noob

Hi. I have a few questions. Im sure these would sound stupid but…

1) who are the devs , i mean satoshi wrote and released the code right. Has the code ever been altered? If the LN is an intregation with the original code … who dod the intregation. I mean there is some sort of community who is handling the…. Addons?

2) read somewhere that bitncoin cash increased thier block size for faster transactions …. Why didnt bitcoin do this ? And if they have thier devs working on the code …. Whoes working on bitcoin cores code ? Was Ln reqlly that important ?

3) btc = 1.00000000 ( eight zeros) if im not mistaken Can the devs or someone change this ? To 7 or 9 zeros ?

4) if 50% of hashing power is controlled by 1 person or entity. What harm can be done ?

4.1 )does LN play a role here ?

Sorry if these questions are retarded. But any info would be good. Thank you guys.