What about putting the line "/cast [nopet] Summon Water Elemental" at the end of the macro instead of the beginning? If the macro locks up cause of pet summon cooldown all the other commands are issued while waiting for cooldown to come back online. Unless a GCD error or un-useable ability in a macro will lock it no matter where it is in the code?

Also, does a water elemental scale in power with the mage's Int/sp? if so, casting the trinkets prior to summoning will be a boost too.