Hey man, I'm not an expert so take this with a grain of salt. I don't think there is a such thing as optimal weight for bouldering. We have similar height and weight, I'm 5'9" at 145. I have never felt that my weight has held me back. Having muscles is always good for making powerful and dynamic moves, and you definitely don't need to cut the weight to climb.  As for effective climbing, I think having muscles and lifting puts you above the average person when starting to climb. However, some other really important things to climbing are finger strength, technique and footwork which everyone learns at their own pace.  Either way, I would recommend you give it a try and don't worry too much about it. :)