I don't believe it's direct mount.
It should come with its own top cap. Yes, the steerer will likely need to be cut. It's not hard to do yourself with the proper tools - you just need like a Park Tool SG-6 and a carbon-cutting blade for your hacksaw (usually available at Home Depot, etc). And some sandpaper to smooth the cut. The benefit of doing it yourself is you can experiment, and not annoy the shop by bringing it in 3 times to cut it progressively lower.
There's no need to have a bike shop install the BB. I recommend something like the Wheels Mfg. BB30 Outboard Angular Contact BB . Super easy to install. Just smear a little grease on, and push 'em in and tighten up with a standard tool.
W.r.t the BB, the only thing that might take shop-type skills is if the frame comes with BB30 bearings already pressed in, knocking those out without damaging them so you could sell them with the frame should you re-sell. Bearing knock-out tools can be a bit "specialized." (though bearings are cheap, like $20 for good Enduro BB30 bearings, so it's not the end of the world to damage them if you just use a hammer and a wooden dowel.)
Other than that, it's pretty a straightforward build. Getting all the housing the right length is always important. Making good, clean housing cuts and de-burring the ends makes for good shifting/braking.
It should come with its own top cap. Yes, the steerer will likely need to be cut. It's not hard to do yourself with the proper tools - you just need like a Park Tool SG-6 and a carbon-cutting blade for your hacksaw (usually available at Home Depot, etc). And some sandpaper to smooth the cut. The benefit of doing it yourself is you can experiment, and not annoy the shop by bringing it in 3 times to cut it progressively lower.
There's no need to have a bike shop install the BB. I recommend something like the Wheels Mfg. BB30 Outboard Angular Contact BB . Super easy to install. Just smear a little grease on, and push 'em in and tighten up with a standard tool.
W.r.t the BB, the only thing that might take shop-type skills is if the frame comes with BB30 bearings already pressed in, knocking those out without damaging them so you could sell them with the frame should you re-sell. Bearing knock-out tools can be a bit "specialized." (though bearings are cheap, like $20 for good Enduro BB30 bearings, so it's not the end of the world to damage them if you just use a hammer and a wooden dowel.)
Other than that, it's pretty a straightforward build. Getting all the housing the right length is always important. Making good, clean housing cuts and de-burring the ends makes for good shifting/braking.