Is this ok? I only plan on using 10 psi. I see hose labeled for boost but it handles 250psi!!!! I used vacuum hose on my last setup and I was pushing around 15 psi for a couple months. The hoses run to the fuel pressure reg., msd box, and the meth injector controller. Is it ok to T-off to these or should they have their own source. Would this affect responsiveness?

Yeah vacuum hose will be fine.

If you're really worried about it, and want to do it on teh cheap you can use brake line, and then just short sections of vacuum line where it needs to connect to other parts. I did this with my BOV on my last set-up after having a vacuum hose on there for a while and noticed the BOV was much more responsive, opened quicker.

Ideally you should have a dedicated source for each device, but T-ing off will be fine.