I recommend running your DIN at the chart suggested if you are only type 2 skier. If you are 3 or 3+ you should be able to decide for yourself if you need to tighten them.
All bindings are set to the same standards and will release the same. A Marker 7 will release at the same point as a Look 7. (this is all measured in Newton Meters by the amount of force it takes to release from a binding). Some bindings do however provide more elastic travel and will give you a bit more room for error. The Marker Biometric toe will want to release you once the boot hits a certain point. Where as others will allow your foot to tweak slightly and come back to center. Same with the heel releasing forward. Look/Rossi have the most amount of elastic travel in the heel and therefore allow you to come more forward without completely releasing. Think about it as a margin of error. Some might be considered a "safety" binding whereas others would be considered "retention".
The FKS 140 should not be too much. I highly recommend running a pair on all your skis.