How to spend my free time in banking?

I've been incredibly blessed to have been given an IB summer analyst stint this summer at a solid BB group, as well as an off-cycle IB internship this winter. It's been since the early fall that I locked these 2 positions up, and I've given myself these past 9 months to prepare for my summer analyst experience and take a relative break from the recruiting madness.

I want to get back on the grind, and my experiences so far (loved my IB internship) and conversations with alumni have convinced me that a PE career is what I'd like to pursue. However, since the recruiting cycle for PE won't start until (the earliest) 1.5 years from now when I'm a couple weeks into an analyst program, I'm not totally sure where to put my efforts to boost my chances at PE in a few years.

Some obvious things I can work on are maintaining a high GPA and getting good experience this summer. But some other ideas I had were:

1) studying for the GMAT and take senior year

2) off-cycle, during-school-year PE internship (how would I go about nabbing this opportunity?)

3) starting some club/student venture that would show my investor mindset (any ideas on what I should be aiming for)?

4) contacting alumni in the industry (should I be requesting their help? How is networking different than IB)?

Thanks if you made it this far - any perspective is appreciated!