Raging Blast is dead branding. I think Sparking Zero is a good choice because if they called it Tenkaichi 4 (or 5 if you include TTT, 6 if you include UT etc) it may create this perception that one ought to play the preceding games first. This essentially serves as a hard reboot for DBZ fighting...
Basically some old disfigured guy helped Guts but ended up being executed. Guts could have very easily prevented the execution but decided to watch it instead.
Because Guts was traumatized both by his early life and then the Eclipse. He allowed himself to be vulnerable and accepted by a group of people again only to feel betrayed again on a grander scale. This leads to a mentality of relying solely on oneself and his strength. He becomes a prick, and...
I think new content will continue as usual. I don't think it should. Dragon Ball should have ended after BOG or remained limited to occasional movie releases.