1. Every blank is different. I would caution about the idea of "fast", which is disastrous until lots of experience with different tools and wood/resin/segmenting is under the belt. In another post just a couple of days ago, someone (was it you?) mentioned several blowouts in drilling on the first batch of blanks. The cause to experienced users is obvious: speed and inexperience. On delicate blanks such as snakewood, some people drill the hole over a period of two or three days. (Minuscule Heat build up can cure cracking). Thin blanks don't have the wall integrity (strength) to hold its self together with fast drilling. Same thing happens with some blanks in trying to get them to size quickly.
Examples: Desert Iron is hard. Rushing it can ruin the edge of the tool, or potentially cause a blow out, while watching the blank develop into beautiful shape and color. Segmented blanks: Rushing will result in blowouts for sure. Some resins won't let you rush or chips will jump out. For me, there is as much enjoyment in the journey and what I see developing, or what I learn with a new segment or unusual wood/resin/material. It is fun to watch the blank develop while getting to the final turn.
I often do get mine "round" quickly in using Carbide and then switch to HSS.
1.B On occasion, I will run a blank ( hard desert iron wood) across my router table with 1/4 inch radius round over. Getting to size is best done with turning, stopping, measuring with calipers, turning again, measuring and going down to .005 below the size wanted and build back up with CA or other finish to the precise size of the center band or nib end or clip end. CA does have a thickness value on it, so, many people allow for that to get back up to size.
2. Other methods? In casting, some cast round blanks but I don't think anyone casts to size of finished blank. I mentioned using a router above.
3. I have three carbide tools and use them on occasion for rough turning on hard woods and resins. However, I change to HSS tools once rounded.
Woodpeckers, a very expensive and precision tool company (and well respected) as well as a few others have been advertising something along the lines of "nano" molecular/crystaline(?) carbide turning tools. Carbide by its nature has been difficult to get as sharpe as well as high quality HSS and similar tools. As much as people say that the carbides are as good as HSS, so far, I (and I know others) can feel the difference in well sharpened and honed HSS vs a new/good carbide. The newest carbides claim (insinuate) that they are as sharp as well tuned HSS. I haven't tried the latest such as Woodpeckers say, so I cannot compare.
That said, there are blanks, especially segmented cast or wood with aluminum/brass/copper in it in which sanding causes tremendous smearing and color changes in the surrounding wood. The only way around that - is to sharpen so sharp until it cuts so smoothly that sanding is not needed. A few people do this. No sanding needed, but fresh precision sharp is a necessity, and that doesn't take more than a literal few seconds to attain.
Back to your question: Carbide does not need sharpening (honing) every minute or so like HSS does. In general, Carbide works and exceeds production turning better than HSS for sure, and in my opinion the Carbides are worth it for what they do. Still, the HSS has its place. If nothing else for me, HSS is what I use to finish turning to size - as it eliminates sanding in some or many instances - such as segmenting.