Both adjustments will affect the angle to some degree. The bridle adjustment will have the largest effect, moving the bridle point down (heavier) will increase the drag on the kite causing it to fly lower. More bow will allow the sail to spill more wind decreasing lift and increasing stability. Careful with the bow, too much and the kite may become too stable to recover from a dive if you get tipped.
I Like my fighting Rok's to pull hard so they can take line out quickly and to drop like a rock (pun intended) when you release line, but I also like them to fly at a high angle above the other kites so the first two traits can be used effectively. It's a balancing act that I'm not so good at, Richard was our tuner and always had the kite spot on.
That smaller Tyvek Rok you did first is a great fighting kite but I have issues with organizers allowing those to fly in Team Events where the minimum size per AKA rules is 5 feet tall, I still prefer a traditional 2 meter size.
There's a lot of good information on Rok tuning over at the KAP (Kite Aerial Photography) Forum, they might be looking for different traits then fighters but we can sort of reverse their solutions. Here's a starting point http://arch.ced.berkeley.edu/kap/discuss/comments.php?DiscussionID=2651
Have a great time, there is nothing as much fun as a Team Rok Battle, and remember ALWAYS CLAIM VICTORY ... first kite down wins ... right?
Our team spent many years only winning the ribbon for "Team with the Least Self Respect" ... err ... "Best Costume" before learning from a Manja Fighter how to cut properly, then we actually started winning until the rules and scoring started being ignored. Oh well, any good Rok battle is a win IMO, I'll be on the feild as long as I can run for an hour in the sand tugging around a 2 meter.