Using a combination of letters and/or numbers to sound out the answers, can you solve the clues?
1. Not difficult
2. Unoccupied
3. To do extremely well
4. Defeated
5. A number (use only letters for this one)
6. A sport (say it fast and it just about works)
7. Freezing
1. Not difficult
EC
2. Unoccupied
MT
4. Defeated
B10
6. A sport (say it fast and it just about works)
OK?
7. Freezing
IC
1. Not difficult
EZ (American pronunciation)
3. To do extremely well
XL
5. A number (use only letters for this one)
AT
(American pronunciation) Never! ::hand to forehead in melodramatic pose:: 
I always loved the Cat in the Hat ending up with a non-rhyming "zed", and can never be quite as fond of it with a "zee" even now that I know that was the intention 
Oooh Dr Seuss! I never really took to him but did enjoy reading about the tweedle beetles and their bottle battles to a small STPD deja vu - did I post that recently on here - just ignore me if repeating self
well done Helio and Eccs 
I liked OK for a sport (Hockey! said like Manuel from Fawlty Towers 
) and here's an alternative:
10S