Across 
3. Unable to read or write.
6. Communicate or match up.
7. Wild.
8. Sort of a whole body 10D.
9. Not likely.
11. Not very practical.
12. Could be a noun or a verb.
15. Not yet ripe.
16. Not thinking clearly.
18. Verrrry tempting.
20. You have one at the bank.
21. Homework is a type.
22. Unable to be gauged.
24. Guarantee.
26. Frustrate.
27. Against the law.
28. Used to.
29. Do something 27A and this will happen.
30. Features.
Down 
1. Go with.
2. Untrustworthy.
4. There's only one.
5. Flowers make a nice one.
10. Wave your arms wildly.
13. Treat like a kid.
14. Selection.
16. Sort of like psychic.
17. Newcomer to a country.
19. Not standard.
23. Try.
25. Self conscious smile.