Alternatively one could keep the casting penalty benefit, but do something about the crazy OB bonus that Spell Adders grant sort of like a freebie to directed spells, unlike all other spells with respect to Spell Adder use.
Note - Direct Attack spells were initially presented in the HARPer's Grimoire, which was later pulled from sale and replaced with HARP Codex. In Core and CoM rules there is no such thing as a direct attack. Spells were either Utility, Attack (which always offered Resistance!) or Elemental Attack (which resolved on the various elemental crit charts). The Elemental Attack is very similar to a Direct Attack spell - but the difference lies in the Damage aspect.
Elemental Attack resolves on standard elemental crit charts with scaled damage based upon the success of the roll.
Directed Attack in one spell resolves similarly (and that doesn't seem to be an issue - Scattershot), and then there are those with preset fixed damages including special damage and the ability to scale the damage (Thorn Blast and Magic Darts), and finally there is Web (which upon re-reading is an uber-powered spell that assumes a hit every time and only allows the target a Hard Str Maneuver to break free - should include either a Magic RR or a roll for a successful hit) and Web Bolt (which doesn't even reference either a Maneuver to break free or the RR or hit roll)
The Web Str Maneuver is 1d100 + (StrBonus *2) with a -20 Hard Maneuver penalty and you need to break 100 to succeed. That means you need to either OE or you need to have a StrBonus of +11 or more. Assuming your race gives you a +2 or +3 (one of the stronger races) that still requires a Strength of 100+ to succeed without an OE.
So perhaps these 4 spells should return to the roots of HARP magic....
Make them all resolve similar to Elemental Attacks (without the uber-scaling options!) and for scaling options increase the damage size (Tiny/Small/Medium/etc.) and if giving special damage types apply a secondary crit.
For the Web spells, roll the attack (DB should not include armor bonus) check the result on the Percentage Results and then allow a StrBonus Maneuver on the Percent column to try to break free.
ex:
Caster has a skill bonus of +77 and Target has a DB of +80 (but only +20 without armor).
Caster rolls a 30, adds 77, subtracts 20 = 87
Percentage column reads 80 - therefore target can act at -80 for any maneuver or target can attempt to free himself with a Str check. Strong guy with +10 StrBonus goes for the StrCheck.
Rolls 56 +20 (StrBonus *2) = 76. He has reduced the web by 70 and resulted in his left leg still being caught. Next round he can act at -10 or free himself further.
I haven't playtested this, but just from running it in my head it seems to be a much more legitimate rule than the way the spell is currently written. Feel free to share comments on it.
ZuS - I know you won't want to add this as it is a house rule - but I think it might be a house rule you guys can easily accept and implement (at least the part about modeling after Elemental Attack).