Re: Bulba, Squrt or char?
Bulbasaur has always been bad for me early. Why? Vine Whip has only 10 PP. And you have to last with that until you get Razor Leaf at 22 (or 20 if you choose not to evolve into Ivysaur before then). It makes long travel tedious because you either need to trek back to the Pokemon center or default back to Tackle, which you'll have to do anyways. Because wild Pokemon that are plentiful in the beginning of the game include tons of bugs (through viridian forest) and tons of birds (pidgey, spearow, and their various evolutions remain common and annoying throughout the game.).
And then after Razor Leaf... Well, you're done. That's the best grass attack it gets that doesn't confuse it, not counting Solarbeam, which is bad unless you're running sunny day (which makes fire attacks, which venusaur is weak to, even better, so I don't recommend it.) Don't use Petal Dance.
Petal Dance has 90 base power and is STAB, which is exactly the same as Sludge Bomb. Use Sludge Bomb instead. Razor Leaf will be more than enough for ground/rock types that you run into, and there's no reason to lock yourself into a move and then confuse your Pokemon when you could have used Sludge Bomb for the same amount of damage. I would say that, but I guess the game developers hate Venusaur with a passion, so you don't get Sludge Bomb until post-E4. So I guess you're forced to use Petal Dance. Unless you go with Razor Leaf.
That being said, more on Razor Leaf.
At the time you learn it (lv22) it's 55 base power is highly respectable. But as you get later in the game, it's just lackluster. You can teach the Squirtle line surf (95 bp) or hydro pump (120 bp but accuracy loss) or the Charmander line naturally learns Flamethrower (95) at 34. Flamethrower is arguably the best fire attack in the entire game due to balance of accuracy and power, and you get it before you're even Charizard.
You can argue that sleep power, stun spore, and various other support moves are good, which they are, but it's much easier to get through the game with a powerhouse starter than a support starter that, though being good against early gyms, is pretty slow to start for the first part of the game vs wilds and random trainers, due to low PP and the types that grass isn't very good against being very common there, and then it's STAB move selection late in the game in 3rd gen is just terrible. Poison is a terrible offensive type as well, being good against next to nothing and bad against too many things. It is Venusaur's better STAB move in third gen though, due to Razor Leaf's bad BP. It's the same BP as Petal Dance, without the downsides. Use it. Unfortunately, you won't get it until the Sevii Islands. Way to go, Venusaur. You don't even get your best potential STAB attack until after you've already beaten the Elite Four. I just can't even describe how terrible this is. This basically forces you to either sit around and Petal Dance your head off at everything (which, most of the time, you'll probably live through it.. in-game isn't very hard.. it's still very sub-optimal.) or sit around with 55 BP Razor Leaf. Why? When you can use Squirtle or Charmander and get free Surf/Flamethrower.. ><
I have never considered Bulbasaur to be the "easy" starter, and game guides that do are doing it solely based on matchups with gym leaders, which should not be difficult at all. You have 6 Pokemon slots if you need them.
Squirtle is a good choice. Good, but not as good as Charmander.
-First starter to learn a STAB attack with Bubble at lv7
-Water Gun has 25 PP like Ember, so it doesn't run into travel problems like the lame 10 PP on Vine Whip
-Sturdier than Charizard
-Better damage output at high levels than Venusaur due to superior movepool. Surf > Razor Leaf. It's not RBY anymore, it doesn't crit 100% of the time. Surf > Petal Dance in both power (slightly) and not being stuck Petal Dancing when the nextLo Pokemon that comes out is Flying or something. Doesn't make you confused.
-Ice Beam or Blizzard via TM helps to cover its grass weakness and provides ANOTHER 95 base power attack.
-Water/Ice is a much better attack combo than Grass/Poison or Fire/Flying
-Gets Mega Punch/Mega Kick early via tutor if you want, like Charmander. (Bulbasaur is the only starter who can not learn either.)
-His first STAB attack is slightly weaker than the other ones, but he gets Water Gun at 13 (a few levels later than vine whip on bulbasaur)
-His stat distribution is slightly more defensive, making him somewhat slower to kill things than Charmander, but still better than Venusaur
-More TM-dependant than Charizard. Ice Beam and Earthquake are great for covering Grass/Electric weakness but are TMs that many Pokemon could use. May want to save them.