I'm very sorry, new version with bugfixes and better diagnostics was almost done when I was distracted by other, non-crypto things

i have problems with a rig with 4 GPUs (working fine in sgminer).
This rig hashes the same as a 3 GPU rig.
what should i check?

(Win 7 64, catalyst 14.4, proper DLLs in smelter dir, Gigabytes 280x, -g 4 -w64.)
Probably one of GPUs overheated and does not work. Try to lower clock speed for all cards, then raise it back card-by-card. There is no speed settings in the released version, use external tool (Afterburner or something) for overclocking.
Warm algorithm, how to adjust settings fan?
I don't think its possible with this version

Yes, not yet
why is that smelter last official miner only get me 5-6 mh on nicehash?
First of all wait a bit, pool calculates speed by accepted shares, give it some time (~ 5-10 min) to catch up. Look at miner window, may be there are some diagnostic messages about rejected shares and h/w errors, if yes, post it here. Lower GPU clocks with Afterburner and see if the speed raises to expected for your card.
If nothing will help - take my apologies, I'm very sorry for abandoning the project, and wait for new version