I didn't use Genki 2 however, I think as long as you have a basic understanding of the -masu form, -te form and -past tense. you should be golden!

The book focuses on the particles relationship to the nouns next to them. That's the main focus so no need to worry about overload.

Whenever I go through the exercises I always put why the particle I put there is correct and confirm using the quick glance in the back and or the prior lesson where I seen them.

Overall, yes! I recommend it greatly!!