It will most likely be ok. It's not super easy to mess up sinewing in my opinion. In regards to it coming off. Depends on what glue you use, but I've never heard of sinew coming off a bow I think. I might of once when the sinew was drying, it might of lifted off as it reflexed, I think I heard someone say that before, but I could be wrong. It's probably dry-ish/tacky-ish by now, but if not just stick with it as the glue slowly gets tacky and rub it down to get rid of air bubbles. If the sinew is'nt sticking well it may be the glue is to hot/watery/not ready yet, but sometimes when it cools it gets tacky and sticky even though it's watery and not sticky when hot. I still don't glue anything until it makes my fingers stick together, usually beady and makes little glue balls at that point which is annoying but I know it's good and ready then, I just heat it up a bit on warm on the stove if it starts to get too beady. Probably has to do with water evaporating. (this is for sinew/hide glue) Make sure to apply a couple extra heavy layers of glue on top of the finished sinewing as it's annowing having sinews lift latter on. It will probably be fine.
"Also, seems that some small spots aren't sticking well??"
It don't hurt to be generous with the glue, for me it never has anyway. If the sinew it falling off or sliding to much, try putting more glue on. And smoothing with your fingers real good, coat the whole bow in glue after each layer of sinew. That is if your doing more than one layer of sinew.
