being able to send a 100 character mesage when sending coins ( to beable to tell people were it is from / can be used to send mesages using a small transaction
No good. The amount of blockchain bloat created from that combined with 30 second blocks would quickly make the chain unusable.
There's been talk of a bitcoin based messaging protocol, but combining a currency with that would be suicide.
FastCoin is working well and that has a 7 sec block time, so I think 30 sec will be more than ok !