Question about bi amping front components.

[YarisSedan]

So i have components on the front that are on a passive crossover. The crossover has the option to be bi amped. Would it be better to run new wiring from the second amp to the speakers on the doors and let the amp crossover LP handle the mids. And another amp separate to the tweeters setting the HP setting to the tweeters.

Although easier is it more beneficial to just let the passive crossover handle everything.

Another question is to get the signal for the speakers in my door should i be getting a Y splitter to split the signal for the front 2 channels. The deck is a pioneer that has 6 rca outputs. 2 for the front which are currently setup for the front components and the 2 sub outputs for the rear subs. So i have 2 rear channel outputs that are still available. Will this mess up my sound staging if i use the rear rca output to power the mids in the doors while the vocals from the highs are by the pillars from the front rca outputs.
Another question is to get the signal split for the front is there any particular brand Y splitter i should use that is good.