Again, being someone who really went hardcore to try and do something like this, I found three extremely hard-to-get through flaws.
#1: Lack of graalians:
You're only going to have the graalians who WANT this server, if you ever go classic and EVERY trial flocks to your server, you probably STILL won't have enough people. You'll need REAL people to run your business's, and try not to go too nuts on NPC's, else you'll be considered modern.
#2: Too much confusion about if its modern or not:
When I did this server, I only had ERA supporters. Well go figure, when you have Era supporters, you'll always have a group who wants guns, pking, crime, and a group that doesn't want it, and the group that did NOT want the guns and such were the minority group, think about a 4:1 ratio.. I think you'd pick the 4.
#3: Just generally hard to do:
You'll need some kickass systems to even get CLOSE to this, some of the systems that I thought up a long time ago would make every member of the GST say: "WHAT!?", not to mention the lack of good SFX teams. You'd also probably want to go VERY customizable custom bodies, the kind that would make old Atrius bodies look like plain graal bodies (Glasses, hats, gloves, shirts, boots, jewlery, piercings, makeup, pants, just general clothes..)
Thats a CRAPLOAD of gfxers.
Then ganiers for custom bodies are ALSO hard to come by, not many ganiers are use to REALLY customizable bodies, not just arms,shirt,legs,hat..
Basically I'm explaining to you that it's been tried, it's been hard to do, and unless graal has a 543205205025023 player growth spurt, then you'll still have NPC's running your systems... And really, that's not too "real life" now, is it? (Unless you're talking about them computerized systems ;o)
But hey, I'm not going to disown you, kick you to the corner, and then laugh at you, because you're bringing back a REALLY good idea, just a hard one.
If you ever want help or want me to send you my ideas, give me a PM.