And how would I exactly do that on my phone? I have a rooted android.
if it's rooted, proxydroid should be good for the purpose, don't use your phone built-in proxy settings to set a proxy, it's not a 100% certainty that the ig app will go through it
it's better not to mix the ips too much, although i also use 2 aged ig accs with different ips, because i have two connections, a cable with a static ip and a 4G/LTE connection with dynamic ip, as long as it looks natural (meaning you access your accs from only a few ips which are close to each other geographically), i don't think that you'll ever encounter an issue, but better be on the safe side, so if you can, just use the same proxies for your accs and don't switch between them
but you can upload pics using FL too, check the user manual, if you didn't figure it out how to do it by now
on the other hand, if you want to manage this few accs only, you can easily verify these from phone numbers which are in your/your family's possession, so you'll be able to re-verify the accs when and if you will be asked to do so