Zhulien:
Tests are done now, as a result it seems that indeed the gradients slow things down, as i mentioned below. According to AmigaMancer, Intuitin Skins itself don`t slow down things significantly.
But in your case, having only 64 MB Ram, it might be a good Idea to disable things which eat ram, like backdrop Pictures and such. Also those mentioned "light" skins which does not have that much bitmaps.

I am curious is there enough ram left for proper usage? (btw, for our
"Newbies" :D )Tokai`s Statline Tool is an excellent App for Displaying different Stats like memusage, CPU Usage and much, much more.)

Oh, before I forget, The default Skin is Jobbo`s work. (It is ferox I supose?) He is the master of skin design, I really whish I had his talent ;)