I wouldn't say that the grit I use or good aquarium gravel is sharp, the pieces are actually rounded. I literally put some under a low power microscope to look at it closely. The only truly sharp substrates I have seen were some of those horrible coloured (black, blue, red) artificial things which some people seem to like. I think they are actually made from some sort of crushed rock (or even a glass-like substance) whereas natural sand, gravel, grit or whatever all originated from river deposits and were rolled about for years (or centuries!) and therefore any sharp edges became rounded.
I think the secret to getting a fast cycle is to have plenty of bacteria to begin with. The people who have problems seem to be those who start with a clean tank and tap water, neither of which will have many (if any) bacteria to act as a starter culture. I only use dirty water from an established filter, soaking the new filter sponge in the water, but making sure that lots of bits of "muck" get into the new sponge as the bacteria will be attached to these bits rather than floating in the water. It's easier than chopping up an existing filter. The soil in the substrate and the plants will also help. Whatever, it only took me a week or so to cycle each of my tanks, though I left them a bit longer before adding fish as I wanted the fish to go into an already settled system.
I would definitely put the plants in first, I think it's a myth that they interfere with the cycle, or at least a case of "much ado about nothing". I put my soil layer in, then the gravel on top, then any bogwood or rocks. I add a little warmish water to warm up the substrate. I then plant the plants, it's much easier to do so before you fill up with water. When the tank is full, not only do the plants tend to float away as you try to push them into the substrate, but working with half of your arm in the water isn't particularly convenient ................. Once the plants are in, add a bucket or so of water, using the usual method of pouring it onto a saucer to avoid disturbing the gravel. The water might now be rather cloudy, if so syphon it off and then fill with clean water. When it's full and heated up to temperature start the cycle with ammonia as normal. By the time it has finished, the plants should be well rooted and growing so that your fish go into a developing ecosystem which should be more stable than one with bare substrate, plastic plants and "ornaments", which relies entirely on the filter and requires lots of maintenance. This has been my method for the past couple of years and I've had no problems in spite of rarely changing water or vacuuming the substrate, a change of about one bucket of water every couple of months is the most I do, except if I am adding new fish. But I am meticulous about filter maintenance.
For plants, I'd stick to easy ones such as Hygrophila, Vallisneria, Sagittaria, Amazon Sword, with Java Fern attached to bogwood or stones, the more difficult plants (including the red ones) do require a lot more trouble with regard to light, fertiliser, Carbon dioxide and trimming. I'd buy loose plants rather than potted, they are much cheaper and take very quickly. If you don't have too strong a flow across the surface, then the floating plant Amazon Frogbit will do well, it is fast growing, a great user of nitrates and fish do seem to enjoy its shelter. I do have bogwood in all of my tanks and I think it does have some beneficial effects as well as looking natural.
When the cycle is complete, I'd start with a decent number of fish rather than adding them in dribs and drabs. In fact, I stocked most of mine "fully" in one go, working on the principle that the fish I bought were only about half their adult size and so I was actually only half stocking to begin with. The fish have subsequently grown to fully stock the tanks as the tanks have matured which seems to me a natural way to do things.