Like hexa said: When you run the client and server at the same PC, many times the synch gets so messed up that spells just don't work...you have to try them many times before 1 of them works.
Setting the java priority to high helps, but you may notice your client lagging a bit, or taking longer to load.
If all you want is to change your stats (str, dex, con, int, wit, men), you can give your GM char skills 9001 to 9006 each at a fairly high level (around lv40-50).
Basically, each skill corresponds to one stat and each level of this skill corresponds to a +1 bonus on your existing stat. If your Str is 40 and you give yourself skill 9006 with level 50, your str will become 90!
CAUTION: Try to keep your stats lower than 99! Going higher could cause wierd side-effects and break your char.
Otherwise, if you trully want an all-in-one buff, what you need to do is:
Find the folder gameserver/data/skills
Open the xml files in there and find the definitions of the skills you wish to use. Copy these aside.
Next, start merging the spells into one. You'll have to be smart on this. Make sure you combine them properly (and some combinations may not work at all). Your final skill needs to look a lot like all other single skills. It will only have 1 skilltype, 1 target type, etc etc,but many effects.
Finally, take any one skill you do not plan to use normally, and replace its definition with the super-skill you just created. Add this to your GM char.
I'm a joyful, merriful, playful, curious, young, little elf!!!
I'm also a High(tech) Elf, (computer) wiz!
) 