Yes but only via egg move.
Salamence can only learn Hydro Pump as an egg move in Pokemon Emerald.
No, Salamence can only learn one of these moves, if u want a hydropump, get a male gyrados, kingdra, seedra milotic,,, these pokemon must have a hyropump, and a female salamence if u want a dragon rush get ur self a male garchop which has a dragon rush move and female salamence so the egg will become bagon
Lv.40
Floatzel cannot learn Hydro Pump.
Quagsire cannot learn Hydro Pump.
No, Dragonite cannot learn Hydro Pump.
Azumarill learn Hydro Pump at level 57.
No he does not. The only way to get a Swampert to have Hydro Pump is to train your Mudkip to level 42 without evolving it. Then he will learn Hydro Pump, and then you can evolve him into a Swampert that will have Hydro Pump. (Emerald/Ruby/Sapphire)
Somewhat, bagon does not "learn" hydro pump, however it is on itss egg move list so it can inherit it. and yes gyrados must be a male and must breed with a member of the bagon family, who must be female, in order to have the off spring to know hydro pump. (although i really see no point of having hydro pump on my move list other than showing off, because it doesn't get me any type advantges that i alredy have)
At level 40, Kingdra is suposed to learn Hydro Pump.
Swampert does not learn Hydro Pump.
Lvl. 46 in blue/red/yellow Lvl. 49 in fire red/leaf green/ruby/sapphire/emerald And not sure about the rest... Hope this helped