Yes, they are considerable, but they don't really add up to the elemental prowess. However, I didn't read that it is only one slot, so I guess it is okay. I don't need to play the server, I am just saying that anyone can get to 99 sinX relatively easy, so in my opinion, it isn't really a con. I didn't say the others were not considerable.
There is no need to play on the server to know and or state any of what I've said. Past experience is enough. It's like telling a just retired Pharmacist he doesn't know anything about medicines.
I was just stating that some of the cons are trivial, and that the elemental idea had unbalanced sin in previous versions, so perhaps it needed to be looked at. In truth, the one slot counts as more of a penalty than both the flee reduction and level restriction combined.