At the same time time attacking and casting a spell means two actions in one round, and is in general not possible. R: Touch spells are typically not cast on resisting enemies in combat, unless you have one or two grogs to restrain them.
Triggering an item to attack something is roughly the same as casting a spell - unless you design a highly dangerous 'mine' type of item, like one which goes off every time it touches something with the right part.
In the latter situation you might turn yourself into a spar torpedo boat, attack somebody with that part and hope that nobody else touches it before: your SG will adjudicate botches.
It wouldn't yet give the enchanted item a target, would it? So you need to say first the command word, that better be complicated enough to not get the device primed accidentally, and afterwards hit with it, in the same round - right? That is at the verrry best an attack with much reduced chances to hit. Think of Kendokas having to announce their strike before performing it.
It poses the same problems, but usually requires that you drop your MR for the item to read your mind as well - in the middle of combat. Really risky.
With all precautions taken, attacking with an enchanted device without incurring penalties for weirdness takes the same place in combat as casting a spell.
Before putting yourself at the mercy of your troupe and SG with tricky proposals, you might consider ArM5 p.173 Defender, and in combat become the character defended by your shield grog.
Hi!
OP may be referring to their magus’s Talisman, which gets around this problem with P:Range, and since InMe is one of the strengths of the character eldarin might be posing these questions for, it looks very feasible, and useful for further InMe-triggered effects .
Your talisman's effects still need to overcome your MR, right? And that MR typically grows over time, while the Penetration of instilled effects doesn't. So were back to dropping MR in combat for your talisman to read your mind, right?
Right now I'll still have the problem that I first have to hit a target though. Too many abilities to have to have - not very high scores and an especially low score in weapon.
Performance magic in The Mysteries p29 mentions using Brawl or Martial abilities to cast spells, and that you take three extra botch dice and treat all non-botch rolls as rolls of zero. So say you don't have Performance magic, you'd need to take a penalty for replacing normal movements with a combat move to touch your opponent and risk all those extra botch dice...
Take a look at the accumulated errata for ArM5 over some 12 years here.
Consider, how easy it would have been to errata those three lines you don't like - but they are kept, and don't lead to contradictions.
This does prevent your troupe in no way from taking the responsibility and overruling them, or course.