Nice pic Sidebuster!
Here's another thought. Watch the old Ben Pearson, Fred Bear, Bill Negley, Howard Hill, etc. etc. etc. movies.
Some of them (Negley and Hill) shot very heavy weight bows, but none of them were getting blistering speeds. I don't recall ANY of them mentioning how fast their arrows travelled. They seemed to do o.k. killing stuff and some of them were pretty good at shooting at targets too.
Back to the question, does speed matter? If you are asking for opinion, obviously it does to some folks. Admit it or not, "speed" is a big selling point, both on this side of the sport and the other too. The guys in Primitive Archer would probably argue that dead is dead, no matter how fast the arrow was going when it went through the vitals.
Does speed kill? Not by itself, and it isn't required in extreme portions to do the job.
Do some folks shoot better with a faster bow? I guess. I've shot some of my best ever 3-D scores, including wins at the Howard Hill and TN Classic, with selfbows. I've shot much higher scores with selfbows than some other folks did with much, much faster laminated bows. I've shot two classes and had my selfbow score be better than my other score. So, just like speed alone doesn't kill, speed alone isn't accurate, and isn't required in extreme amounts to be accurate. The young lady I mentioned before couldn't have been getting 150 fps--she has a very short draw and was shooting about 18 gpp--but she cleanly killed deer, beyond 20 yds.
Bottom line, before the discussion got off track, is your set-up will be fine for deer as long as you do your part with tuning, sharpening, and accuracy.
Enjoy yourself and go kill a nice one!
Chad