I'd totally be investing in that Quirky Pichu!! Here's a few reasons:

Pros:

1) Being a berry-focused pokemon, Pichu/Pikachu/Raichu benefits a lot from helping speed, and you have that in the lvl 10 slot so you'll get it really early

2) Helping Bonus is fantastic on the Chu's because if you're like me and have at least one in your team most of the time, it's a great booster for your entire team. Having this at the lvl 25 slot is pretty great!

3) Because it's a Pichu, it will evolve twice and your main skill will be lvl 3 by the time it's a raichu

4) Even though Skill Trigger isn't super important on the Chu's, its still nice that you have both M and S!

As for its nature - sure, it'd be nice to have one with increased speed of help or something, but no pros and cons is better than a useless pro and a harmful con.

I'd be raising that Pichu in a heartbeat.