Touche about Repel to get the high-levelled Slowbros out. Anyway, Slowpoke isn't nearly as bad as you paint it to be earlygame (dual STABs is good) and referring to its speed when talking about offensive bases isn't saying anything when its evolved forms aren't outspeeding anything ever unless Quick Claw is kicking in. You may not like using Slowpoke until Surf makes it a hard hitter (and the option of an evolved Slowpoke is there), but it's there, it does things and deserves a mention for that reason. It's definitely no Magikarp, so I don't think that's an effective comparison.
Training 6 Pokemon as a rule leads to a lot of Pokemon becoming inferior than if you had more exp to share around and stealing exp from team mates making everybody else slightly weaker. I'd argue that catching a Heracross alone (not touching upon how good Heracross is here) costs you a lot more experience than catching a lv. 25 Slowpoke to trade-evolve immediately.
I have quite a bit of experience with the lottery - I never had to reset much to get one without spending much money. Magnemite probably makes the best use of the TMs offered followed by anyone with Guts / normal-type.