[Anaraxes]

The main purpose of Malediction is to let the effect ignore DR. That's why it's classed as a penetration modifier.

The ranged penalty in the description of Malediction is only relevant if you have a ranged attack to start with. The assumption the text usually seems to have is that an "attack" is an Innate Attack, so ranged. (Not a rule, just one of those unconscious biases authors and editors have.) But Leech doesn't have a range, so if you want the ability to work at a distance, you'd also have to add Ranged -- at which point the Malediction range penalties (and increased costs) become relevant.

I suppose you could argue that Leech already has the DR-ignoring ability built in. Grappling doesn't penetrate DR, but the base form of Leech works that way -- so why the need for Malediction? (RAW is pretty clear about requiring Malediction+Ranged for a ranged form.)

The other oddball effect is just the extended contact requirement. Leech works on a per-second basis, if you maintain contact for that full second (as opposed to just tapping the target once during your one-second turn). That's part of the "color" package, since it's supposed to be a vampiric ability. The ranged form presumably assumes that you're still draining over whatever the ranged link it -- important when the black beam linking you to your target is obvious (see No Signature if you don't want the effect to be obvious). So, you might add a level of Reduced Time and count that as changing "full second of contact" to "momentary contact", while still taking the usual full action. (Normally Reduced Time on a single action makes it an instant "free action". Leech is the only place I can think of that has the notion of "entire turn" versus "brief touch", both taking up the one action in a one-second turn, yet being somehow distinguishable intervals of time.)