28ac. Maxim accepts English instructions for body-building. (-E-O-E).
29ac. Heartless guard could be cold on sudden withdrawal. (T-R-E-)
Assuming my other answers are correct.
The grid for this puzzle has some mistakes in it (is this a clever way to defeat the credit crunch by printing prize crosswords which cannot be answered??) for 12a read 11a there is no 11d and 12d,...