Maybe (can your chip hit 4.0 on all cores without a substantial voltage increase if at all?).
Probably. (temps likely won't be the most comfortable).
Only one way to find out (try it and monitor your temps/stability).
Possibly, every CPU is slightly different, but, odds seem good already with 4 out of 5 1300X models reviewed on youtube successfully making it to 4 GHz, and quite a few reviewers said that a core voltage bump was not even needed. Good!
If you haven't made the purchase yet, a Ryzen 5 1400 can be had on jet.com for about $140 with their promo code save15. Only $10 for four more threads...