Most worthwhile items & scrolls for a high UMD Mechanic?

[Adelair]

I'm not sure if any of the offensive Arcane scrolls are worth it.

I'm definitely stocking up on scrolls of Heal, Raise Dead, and I grabbed some Haste ones. Shadow Walk might be nice. Since I fight from range I'm considering hitting groups with Sleet Storm so I can hit them with sneak attacks. Maybe hit them with Leg Shot and Tanglefoot to trap them inside the storm.

I've got wands for healing, poison, disease, and curse.

What else should I stock up on?

[Qaliya]

I've mostly ignored offensive spell items, as do most others, because without all the enhancements and such that real casters have, they don't do much.

So it's mostly buffs and cures. In addition to the ones you listed, I like to carry GH, Greater Restoration, Fire Shield and Teleport. At higher levels I carry Greater Teleport which always freaked people out when I cast it on my fighter. :)

[voodoogroves]

I also tend to like (in addition to those mentioned):

Summon Monster 4 ? (Lantern Archon = light source)
Greater Restoration
Protection from Elements

[QuantumFX]

Tensors Transformation: A stacking +4 to all physical stats and Full BaB.
Blur and Shield Wands: They come in CL 10 varieties.

[onivedlav]

Gust of wind, to remove cc spells such as dancing ball.
Prismatic spay, displacement, power word kill awesome for trash with no spell pen even orange named. TS, GH, Heal, blur shield and protect from evil wands... List goes on