Q: Problems with El Capitan10.11.6 and others

Hi, i have a Macbook Pro 15' 2013 late. Currently i installed El Capitan cause in my purchased app Yosemite wasn't visible. After a complete restoring to Maverick on my Greek App store purchase's Yosemite was visible but it pop me up to US store and i couldn't change that, so comport with El Capitan...

I use El capitan about 2 weeks now and i see several issues some of them are minor but they are still annoying, so:
1. After hitting restart OS shutdown properly but it won't boot up back again, i need to hit the power button manualy.
2. On sleep mode macbook's screen and other where connected on powered up about every 1-2 hours or more often, for this one i went to >System Preferences> Energy Saver> uncheck the "Wake for network access".
3. Lock screen was grey, for that i uncheck "Reduce transparency" on  >System Preferences> Accessibility> Display options. But i don't want to leave it uncheck cause i prefer it solid while im working on other screen i can see my menu bar. Also after this change my Lock Screen has different background image no matter if a changed it..
4. Wifi gets enabled after a starting up no matter if i turned it off before i shut down my system. I use ethernet and this is hilarious it does that.

another issues i had with Yosemite also
5. My Gmail's asking password after reboot every time! On Mail app go to >Mail>Preferences> select your gmail on >Account information card go to >Outgoing mail server> on the bottom of the drop down menu select >edit SMTP server list> open card >Advanced change Port: 587, Use SSL: check, Authentication: Password, then under put your user name & password, click OK.
6. Merge files, ooh this is frustrating.
7. Daisy chain, all the rest i wanted was done by many calls to Apple and HP before purchase the screen to ensure they will work together. My macbook has 2 thunderbolt ports, i use one for Ethernet adapter and the other one for my HP Z24NF which is not compatibly with Apples Thunderbolt cable and i had to by from a third party (Delock brand) to work together. All fine till here, but daisy chain seems don't work. HP Z24NF has an output DP that is mirroring the next screen and on the Mac's display options there is nothing found to change that. This is why i bought one screen instead of two, till i solve this issue im not going to by another monitor to hook it up as daisy chain. I know i have many other solutions, use my Ethernet cable on USB port or use wifi, but i won't.

Till now i haven't found any solution for 1, 4, 6 and 7, if you have the same issues or found anything that would help, please reply it would appreciate it.
Thank you.