With the daily/weekly being account based rather than character based, I don't know why story progression is not account based. You need to go through the story to unlock additional zone/region so it can't really be skipped.
There are roadblocks in the main story that deals with weapon enhancement etc, the one that cost a bit is making a multi-weapon. It is 50k to make 1 star multi-weapon and 100k for 2*, 150k for 3*, 200k for 4* - costing quite a bit and it is probably weapons that you won't be using later on. Just presenting a multi-weapon is not enough, the quest actually requires you to make a new multi-weapon each time you get to that point. Because weeklies are account based, I actually had to get N-meseta from my main because my alt could not afford this step.
Please consider toning down the main story line cost if you aren't going to make story progression account based.