Kitchen faucet filter placement

I have a question about where to install this filter. It's just a small under the counter type filter with 1/4" OD in and out tubes, and rated at .5 gpm.
My questions are:
1) If I put it under the counter and install it in-line on the cold line going to the faucet, will it slow down the flow?

2) Could I possibly put it in the basement and install it in-line on the cold line that goes to the kitchen faucet and refridgerator? That line is 1/2" PEX. I'm guessing it's bad to go from 1/2 to 1/4 and back to 1/2?? I would prefer to put it in the basement if possible, just before the split to the refridgerator line.

Thanks for any advice.

a) you are not allowed the flexible type lines you would typically connect to a small filter like that , through the floor
b) yes that filter will slow down the flow considerably, not to mention it may be rated for a fairly small total gallons...meaning replacing it maybe every week
c) that filter is meant to feed a small glass-filler type of side faucet.