fruit-racking, batch-splitting questions

planning this for a while, but now that it's almost time to do it, a couple of questions have been swirling around in my beer.
I brewed a beer, and once primary fermentation has finished, am going to rack it onto some wild cherries. Don't have an exact volume, cause I have a bunch of cherries, but I'm thinking of filling up about the bottom 1/4 of my 5 gal carboy. I'm planning on racking the beer on the fruit, and once it's almost full, racking what's left of the beer into a 5 liter bottle(so I can have a little without fruit).
Now, my questions are:
1. since I will have already taken gravity readings to determine that OG is reached before racking to my secondary vessels, is it OK if I bottle the 5L beer without taking a another reading(this one won't have had anything added, and I'd be trying to conserve as much as possible, since there won't be that much)?

2. how should I adjust my priming sugar amounts? the beer in the 5L bottle won't be more than just over a gallon, and the beer in the 5Gal carboy will be with the fruit, so I'm not sure how much that will be, either.

thanks so much for the help!

1. yes, use about 1/5th
2. do not bottle the fruit-beer until the secondary fermentation is done.

thanks! so then how should I adjust for the fruit-beer, after fermentation finishes of course?

with the fruit beer I have done, I racked onto 2# of fresh raspberries that had been frozen overnight after 2 weeks of primary fermentation. Leave it there for 7-10 days then bottle/keg.

The yeast will eat up the sugars, the berries will turn white and sink. prime as normal, as the yeast should not leave any fermentables behind, and will be hungry for a little dextrose.