I have been working with FCPX since it first came out and have stuck with it through it's initial struggles. FCPX is the quickest and most intuitive NLE on the market, and I wish more people forgave its initial shortcomings.
I believe you're making the right decision using FCPX, especially when it comes to music videos. I have incredibly fast internet, as well as running on an iMac Pro, so I won't be slowing you down with a laggy connection.
I am happy to provide help on purely a technical level, or can give creative input, that is entirely up to you. I definitely don't want to hijack your creative voice.
Hope it works out!