Well it's not like Maria has to really worry about Scatter Beam's range/inaccuracy issues until later floors where peeps need max fire power, even a ranged Scatter Beam chain should kill most things dead early on especially buffed by Peppita/Lenneth. SB's hit problems mainly come from facing chibi sized enemies besides. Since SB doesn't actually take Maria into direct S/R when set to long slots unlike Crescent Locus/Triple Kick/etc it can probably be considered a multi ranged move.
Saying that it might be useful to some people to have a list of what moves are generally considered LR/SR and what not -
Maria-
Short range -Crescent Locus, Gravity Bullet, Magnetic Field, Laser Blast, Triple Kick, Charge, Aerial
Long range-Energy Burst, Radiation Bots, Aiming Device
Multi-Scatter Beam
Other-Symbology
Peppita-
Short range-Charge, Aerial, Kaboom, Faerie Friend, Dream Hammer, counters
Long range- Magic Hook, Instanto Blast, Frozen Daggers
Multi-Dances~
Personally I like to use Power Dance in chains with Faerie Friend/Dream Hammer for powerful offensive cancel combos (you can cancel chain early yet still retain the ATK boost) Since those moves don't come until late though she's probably just going to want to hang back at range and do full dances before cancelling into the next dance for the most part of the dungeon I think. Your mileage may vary ^_^
Yummy supports! *flees*
What all that says about Speed I don't know but I was planning to give Meru Life on F2 anyway, maybe.
With that 0.5 left over I'm waiting to see if Neph will allow Maria or Peppita Common Support Symbols (Healing), I think Maria might be best since Pep picks up healing of her own later on anyway~
(of course this is all assuming if I even get *past* F1 >_>*