It looks like I've miscommunicated something at the most basic level. You, the player, don't play as any of the OVERs. They're controlled by you indirectly, based on the behaviors that you assign to them, the armor they wear, and the skills at their disposal. Instead, you control a playable protagonist (choice from 8) that gains points during missions into maverick-controlled zones.
Once you accumulate enough points to be promoted to Lieutenant, you are awarded a squad of 12 basic OVER-1s. Before you start a mission, you can deploy your OVERs, in any number, into areas of the zone that you've explored, barring any places where you've found a boss. Once inside a zone, you can also deploy OVERs to your current location, or have up to 2 of the OVERs from your squad follow you (within the best of their ability).
I will consider options other than knockback for Wind effects. And, I agree that 14% is not statistically significant enough to warrant using an element. And, it looks like there's something important I forgot to mention, so thank you for bringing that up.
Each additional memory of a given element would increases proc rate of elemental effect. As an example, if we look at the memory slot grid for the basic armor, OVER-1, we have this:
There are 5 different memory slots, each of which can have a single memory assigned to it. The lines drawn between them are called bonus lines. When two memories of the same element are connected by a bonus line, their properties gain bonuses. In our case, we're looking at a +1 bonus for any of Life, Power, Speed or Jump as long as the relevant stat already provides at least a +1 bonus, and elemental effect procs gain a +2% bonus.
So, if we attach a Water element memory (Level 1 Nightmare Razor with +0, +1, +1, +0 and Charge Boost-β) to the upper left slot, and another Water element memory (Level 3 Nervous Demon with +2, +0, +3, +1) to the upper right slot, then the OVER-1 will have a Water-element buster shot that has a (10+4+2+2)% chance to cause a short on hit, and the Nightmare Razor would get +1 power and +1 speed, and the Nervous Demon would get +1 life, +1 speed and +1 jump. Adding another Water element memory to the center slot would increase the chance by another 12% (the center slot provides a +4% bonus, then gains +4% from the 2 Water memories connected to it, and increases each of those memories' chance by 2%), and whatever bonuses of +1 or more it provides would also be increased by +1.
Meanwhile, we have the elemental armors. The scheme for each elemental armor's memory slots looks the same. The Water armor is shown here:
Although it doesn't have bonus lines, it does have elemental match slots. Whenever a Water element memory of any kind is equipped to one of those slots, any bonus it provides increases by +1, its Water effect proc chance doubles, and its chance to use an indicated for skill increases by 5%.
I agree with your assessment on stat values.
The skills are passive. In most cases, an OVER will check for whether or not it uses a skill it has as soon as the conditions of its use trigger, but no more than once per 30 seconds. Times it wouldn't include if the OVER is blind, frozen, shorted-out, in the middle using another skill, et cetera. An OVER has a 10% chance to use a skill they have equipped when the condition calls for it, for each memory they have with that particular skill. I'd suppose a menu would allow you to address the priority of skill uses.
When a skill's memory reaches level 5, the maximum interval for it decreases to 15 seconds (even if it's the only level 5 memory for that skill the OVER is using), and the chance to use it increases by 5% (for each memory with that skill at level 5).
Defense Plus checks when the affected OVER takes damage.
Charge Boost checks when the affected over begins charging their buster.
Recovery Nanites checks when the OVER has spent the last 6 seconds doing nothing.
Magnetic Inhibitor checks when an enemy enters the range of the ability. So do Short-Circuit, Process Inhibitor and Depolarizer.
Overheat checks after an enemy has been in the skill's range for 6 cumulative seconds (not necessarily consecutive, though).