Can I reinitialize specific core services?
Have you tried this app or similar ones like this  -  Fast Reboot - Google Play.

You could also try disabling some apps from auto starting via apps like these - Startup Manager - Google Play

Another thing to do could be to install a custom ROM, which may have lesser bloatware but may come at expense of stability. In custom ROMs you may also have option to disable boot-animations, although the difference wouldn't be much.