Time capsule is not for backup of iphone.. there is no direct link.. apple uses itunes to backup the iphone, which can be either on your computer or icloud. Time Machine which is the smarts of the system is software in the Mac that will backup itunes to the TC. The TC is a hard disk in a router. .it has no smarts whatsoever.
A. Do you recommend buying Timecapsule or going for the cheaper option of an Seagate NAS? (and forgo the dual band)
Nobody but you can answer the question. TC is a more reliable unit for TM backup. 3rd party can work but lots of them have issues. Check via google if people have found the seagate NAS reliable for TM.. you need to use the exact model you want to purchase. The TC is not a NAS.. it is a target for TM backups by laptops. If you store files on it, there is no way to backup the files without using another disk, like USB drive plugged into the TC and manually doing the backup.
5ghz is much faster than 2.4ghz but has very limited range.. ie it is for use in the same room and perhaps the next one.. no further than that. For many people buying 5ghz turns out to be a waste of time, unless you can arrange the router in the room you are working in.
B. If you recommend buying, how should I wire the Timecapsule to the Router, so that I can make use of all the features and speed TC provides? Can I connect it in a way that the Belkin Router is used just as a modem and TC actually becomes my primary router
You can either keep your belkin as the main router.. and just bridge the TC.. that will not hinder its usage at all except for icloud where the TC needs to be the main router..
Or bridge the belkin and use the TC as main router. The ISP must support PPPoE authentication for this to work.. check your ISP.
