I am currently running a Dwf Rng Barb...... I plan on taking DWS and FB2 my questions, which ican't seem to find the answers to are these :

1: Does DWS shot stack with keen or just imp crit?
2: Does the bonus from FB crit mult stack with DWS shots?
3: Can you add the force upgradesfrom the stone of change and the icyburst upgrades from the witner altar to greensteel weapons?
3b: Can you add the upgrades from the Shar altars to a non-greensteel item?

Any help would be appreciated. I am about to lvl into DWS and want to be perfectly clear on my available options before hand. Thank You All and Good Hunting.
Hule