Indeed. Focusing the senses would be an indication of preparing to use precognition or another sense-based power, rather than overtly aggressive abilities like telekinesis. 

As far as how they charge, it really depends. Outside of T1, there are a lot of ways to release a lot of power with no charges at all, such as an outburst of strong emotion (rage, fear, hate, etc) that fuels the power, but leaves you drained in the aftermath, or becoming so serene and at peace that you become one with the force (or close to it). Adjusting those things to fit T1 rules may be a bit of a challenge, and it likely won't look like traditional charges where you actually focus on the ability itself.

There's also the possibility with the force of absorbing the energy of an incoming attack and redirecting it (either back at the opponent or into some other purpose), which could help account for what happens when there are more defensive charges than aggressive ones.