Hm, I can certainly see where that could be effective, as I have tried it from time to time myself, but I often, when the foe is not to far off from the edge that I'm at, and the entire character is slightly over Charizard's head level, just approach them to give them a little taste of his Fair, it blows foes away good.
When they're below, I come rushing down with a Dair to spike them to their doom.
As for recovering safely, air dodging projectiles with good timing is important, and if it is a direct attack from a foe, try mid air jumping to get up to a good level with the target, while at the same time performing an air dodge to go through the attack.
Doing so should get the foe behind you, a good time to Bair the foe off the side of the screen, try to get enough distance between you and the foe, so you'll catch the foe with the flame at the end of Charizard's tail, sweet spotting that attack is nearly as strong as Zelda's Lightning Kicks, but seems much easier to sweet spot, an excellent attack, I am a fan of those strong tail slams.
For your ground game, relatively frequently use his 3 standard attacks, they get off fairly fast, and do decent damage, and depending on the opponent's damage gauge, it can set up well for other attacks for combos.
While Rock Smash can be a superb way to make those damage gauges sky rocket (I've done as much as 49% with one use), going around spamming it isn't a good idea, found that out for myself.
It may deal big damage and have good knock back (especially in mid air, it's pretty much smash attack powered in air, so it can be a good finisher move for recovering foes), but it
is slow, you are briefly vulnerable after starting the attack when Charizard hauls it's head back to smash the rock.
Something else good about Rock Smash, is that it can also be sort of a counter, sometimes when I start the move just before getting attacked, it gets shattered and the foe gets damaged too, but minimal knock back.
Flamethrower can be used very effectively if used at just the right time, it can be hard for the foe(s) to escape from very soon, so it can rack up dozens of points of damage pretty fast, I often find it more effective to aim the Flamethrower attack upwards a bit, seems to reach further horizontally.
And Fly, while mostly used for recovery, it can also be pretty effective for KOing foes off of the top of the screen, that is, as long as the last hit of the move lands, otherwise it doesn't really have much knock back at all, no real KO potential, only the last hit, but imo, it seems pretty easy to land it anyways, the other hits in the middle of the move may just build up a bit of damage.