It's possible to Animal Crossing Bells make enough cash to affix your gear by simply doing a few hours of vhaq and selling the boosters and grinders... A cheap gear affix for 100+ main stat units just costs a couple million meseta.
I've a lot of 6+ slot rares sitting in my storage waiting for used for affixing after I begin doing this. They are just taking up space frankly, ill never return to it.
Even using the simulator telling me exactly what is likely to work, going my affixes and attempting to work out the most cost effective way of slamming different gear together was a headache.
Everything is speculation and you'll need to make your own decisions about what is and isn't worth your meseta. I can not make that phone for you.
The present nemesis and servant weapons would be the buy Animal Crossing Items NT models which came out in Episode 5. The only weapons on EP4 that would replace them would be the 14* weapons which have such a low drop rate they might as well not exist. So unless they did some strange thing, the slave and nemesis weapons pretty much will continue until episode 5.
Holy guacamole I really hope they change the way affix works in new genesis. It's the only thing I wish to radically change from acbells.com.