There is a ton of information on this site as regards the Isomac Venus - just key in "Venus" as the search term and sit back
As far as getting more power from the steam wand, a very helpful "trick" is to initiate steaming just prior to the light going out - very easy with a temperature controller and a temperature sensor (thermocouple, RTD, etc.) but a bit more difficult without. Here you would need to get some reasonable idea of the MINIMUM time required for the light to extinguish - say that it's 90 seconds, just for discussion purposes. Then, start steaming at the 85 second point and you will maximize the ompf available.
As far as brew pressure is concerned, are you reading 14 bar during a "normal" shot? i.e. 60 ml in 25 seconds. I am not familiar enough with the Venus to know the exact method of adjusting brew pressure but assume that it would be similar to the Silvia. Again, not to sound like a smart-ass here but there is even more info on that subject which can be found using this site's excellent search function. A great tip on reducing brew pressure (towards the end of a shot) was posted by Tim Eggers as he described cracking open the steam valve as the shot poured in the latter stages of the shot.