Yes. it would dull the needle pain make sure you give it al least 30 mins to work before the needle stick.
Would help--some. Topical freezing agents help a tiny bit with the needle stick, but the balance of the injection still hurts some underneath. Emla (lidocaine and prilocaine) can help more because it is a topical anesthetic, but it has to be applied well in advance of the injection (30+ minutes), plus the injection would still hurt to some degree, albeit less.
EMLA (lidocaine and prilocaine) = lidocaine. Same stuff. Maybe, though probably not significantly. If you leave an EMLA (lidocaine and prilocaine) patch on a toe long enough that you won't feel the burn of lidocaine, you may not need the lidocaine itself. Depends on the reason for the anesthesia. If you can artfully inject the lidocaine (digit block) with NO epinephrine, you should be OK. It's more a style thing, probably useful for kids who fear that initial poke. .
Elma cream. It can certainly hlep if used by a professional.