Do you think rapid spin should be stronger, have its strength increase when it blows away an entry hazard, and be learnable by almost every flying type? (Yes, this is my idea to try to counter the over-use of stealth rock in competitive play)

Well, this would aim to weaken entry hazards in general, and it’s not really entry hazards that are the problem.  I don’t think anyone really believes that Spikes or Toxic Spikes are over the top; it’s only Stealth Rock that’s particularly controversial, partly because it takes only one turn to set up, partly because it so dramatically tips the odds against any Pokémon vulnerable to Rock attacks (that is, Flying-, Bug-, Ice- and Fire-types).  Honestly, I think the best fix (assuming that straight up eliminating Stealth Rock is out of the question, which I suspect it is) would be to add more entry hazards, with different elemental properties, which cannot be used in conjunction with Stealth Rock (the attack just fails if there’s a set in place already).  Add, for instance, Grass- and Fire-type versions (let’s call them, say, Vine Trap and Burst Mine) – with three alternatives in play, the impact of each individual one will be lessened, and instead of four types being victimised, there will be nine that have to watch their backs.  Of course, anything dealing with type dynamics is difficult to go into in detail, when we know we’re going to have a new type thrust upon us soon…