I'd say go with normal.
Easy is roughly where vanilla would sit, imo, and that is where I'd send a real beginner.
Well, vanilla minus some crap with the vanilla Lv3 tech formula that had a chance to give you a gameover when two random endgame enemies decide to give their FST; you know the 500+ damage to the whole team, just because, even against maxed defense.
In this hack, you should be able to survive two of those FSTs even on hard, at least if you've given defense some thought.
On normal I already expect you to make use of buffs and/or debuffs. On hard they are the bare minimum later.
If you find yourself needing to use a buff even for random fights come Lv50+, that is par for the course.
Of course this isn't a free win. Dolan will probably win at least once even on the easiest setting.
And to avoid the average "expert traps":
black market no longer replaces party building, too expensive for 24/7
Lv1 techs aren't strictly safer to use, neither are Lv2/3 techs always superior, you may want to change those for some situations.
the one or other boss "randomly" hitting for 999 is not a bug
(de)buffs are not only for bosses
Have fun.