Can a grappler become a good striker easier than a striker become good at grappling?

It is hard to say.

Boxing is incredibly complexed and I think this can only be fully understood when practiced. I think alot of technical flaws can be masked in grappling.

It is difficult to say.

 

Yes the level of grappling in mma is much higher then the striking. Guys like Maia, Jacare, Henderson etc are masters at what they do guys like Chuck and Wand are not despite being very successful and effective. Cro Cop said himself that grappling is more difficult to master.