Hi. I'm not close to being an expert on these topics, but my understanding is:
* Yes, you'll need 1 cable from uke to pedal and another cable from pedal to amp
* Tone degrades with cable length, particularly for instruments with passive pickups. So all else equal shorter cables are preferred. But of course, the cables need to be long enough to be workable for your planned playing setup and style.
* Whether a 1 foot cable would suit depends on the size of your amp, the orientation of the input plug on that amp, and on how and where you plan to play. If your amp is 2 feet tall, then probably not.
* Yes, you would use the 6" patch cables for connections between pedals.
FWIW, your next question might be how to order the pedals. Brad Bordessa, who's a member here, has some great suggestions on his website.
https://liveukulele.com/lessons/plug-in/effects/