This is rather subjective but how long do you all think it would take for a newbie to grow to SME level with NetSuite? At least knowledgeable enough to successfully work as an admin.

It depends on your ease with new tools, the way you learn and how you plan to teach yourself (external resources, courses...). Also, about what you mean with the word "Admin" (user management, day to day support ?)

Yes I'd say user management and day to day support, customization, troubleshooting, etc.

User management is easy for the standard features. (a few minutes to understand roles, rights, access management...) Day to day support depends on standard features is quite easy too, since you have Suiteanswers, and eventually the netsuite support. Document customization would require a bit of knowledge on html / bfo, but no big deal for a tech savvy admin. Automation customization, is the big deal (suitescript, suiterest are not easy to apprehend if you don’t already know javascript, oracle db...) If you only deal with workflows, once you understand the transaction schema, you’re good to go.