I would like to know if there is a way (& which way), that one can determine that certain keywords always show in the first place/places on ads and others show in other places.
There's a feature called "Position Preference" that addresses this.
can i set a different busget for a group of different keywords?
Yes, you can assign a different daily budget per campaign.
How can i "force" google to use all of the budget i permit per day? (if at all..)
You can't force Google to spend your money, but you can make sure they don't withhold what they can spend... go to Campaign Settings & check the "Accelerated" Budgeting option.
use the budget optimizer to get G to try and spend all of your budget - but be warned that doing so will lower your roi 99 times out of 100.
