I too enjoyed a lot of these stories in maple, especially when i just started playing. First time i stepped through the Gate to the Future i thought all of it was so cool. I also enjoyed seeing certain npc's pop up in different locations (and times), such as Athena Pierce. The game sure has a lot of cool stories and a lot of them tying into eachother. I think it was in the story of Luminous where you actually get to witness the breaking of the Seals. I really enjoyed that too.
Personally i actually had little trouble with this mission. The terrors seem to spawn quite frequently at least. I did the first stage solo and the other 2 with a bunch of people in a different channel. I can't be bothered to gather determ on mules, so i don't know how bad it would be for them. But my main had no issues with it at all. From what i could tell, the terror monsters seem to get harder to kill, depending on what stage you're on (though i could be mistaken on that). I did stage 4 just for fun and those things took quite some time to die, but stage 3 was rather easy still. I am however a dual blade with 5 mill clean range, so i can't imagine how hard it possibly is for people with less range. I think at some point the giant monster becomes easier than the regular monsters, but i could also be mistaken on that.
As someone who does not use nx at all, i have no proper bpots yet on my equips (all rare and 1 epic, all with garbage stats). I plan to buy bonus cubes with mesos in the future (buying maple points from the meso market in fm), but I've had other priorities with my mesos so far. My main potentials are coming along nicely though. Most of my gear is now unique or leg with 15% luck or better. It means relying on master and meister cube drops from bosses, commerci, bounty portals, legion shop, mineral veins and the occasional events. Extracting useless equips for superior crystals and crafting 1-2 cubes a day also helps. And of course the 5 red and black cubes per month from reward shop. I am currently able to solo both normal lotus and normal damien (though barely).
I hope they put bonus cubes in the reward shop someday. That would help significantly. Though keep in mind that bpot is not really needed to make it far.
260k range at lvl 171 is pretty solid to be honest. I had barely 100k clean range at lvl 200, though i pretty much just grinded before i started worrying about range. Upgrading your gear is a slow and difficult process.
CRA bosses are still far out of your league. Don't expect to be able to solo them for a long time. I was well over lvl 220 before i could take them on. I needed about 1.5-2 mill clean range for the queen, pierre and von bon. My first cvel solo kill was at 2.7 mill clean range. Some people might need more or less but this was my personal experience. Until that time i recommend asking guildies for carries every week.