You say the valves were sticky from the first day? That’s not right — No more than one application of Yamaha’s recommended oil should have been necessary if it was indeed brand new.
Unless you practice “Flight of the Bumble Bee” at warp speed for eight hours a day, you horn does not need to be oiled every day. Depending on the oil and how much you play, once a week to once every few weeks is more usual. Re-oil only as needed –when the valves start to feel a bit tight or sticky or after you clean your horn. Some oils do eventually leave a residue, so over-oiling can also cause problems.
I’ve tried 2 oils on the 72-73 Getzen Eterna I bought last year. Ultra Pure worked OK, but needed to be re-applied every week or so. It’s very light and volatile. I think it evaporates pretty quickly.
Next I tried Monster Oil. I like it much better. It performs flawlessly and I don’t need to re-apply it more than about once a month (or Less). (it was developed by trumpet players in the US Coast Guard Band – I recommend it, but Cass or whatever Yamaha gave you Should work fine.
DO NOT CLEAN YOUR YOUR VALVES WITH TOOTHPASTE! It is abrasive and will wear them out prematurely.
Also, it may void your warranty with Yamaha. Only use warm (not hot) water and mild dish detergent to clean your horn
Take it back to the store where you bought it and ask them what to do. A brand new $1400.00 trumpet should not have slow/sticky valves from the first day.
Here’s a link to a fairly new Trumpet blog called The Trumpet Boards (www.trumpetboards.com). Lots of pro and amateur players are starting to post there. Post the same message there in the Instrument repairs-modifications category. Several trumpet repair techs will see it there and I’m sure one of them will jump on it with more advice.