Lampard had a full season of management under his belt before he got the Chelsea job and Gerrard went north to get experience before he takes on a bigger job.I'd argue that Arteta would be less of a risk than Gerrard/Lampard etc.
No reason he couldn't be boss especially considering his time under pep now
Arteta has never managed a team.
Football is littered with excellent coaches/assistant managers who flopped as managers.