So long as insta-kill contact Locus grenades exist (and do 600 damage to armor), armor will be inferior to shields.

I would have added this in but I'm not sure how bad it'll get, yet. I suspect that when the isk ones come in things will be very very bad. I'd rather not judge until I've actually seen the effect though.
EDIT: The M2 contacts do 900, I believe.

Contacts seem to do a lot more damage than suggested, specially with the explosive % increase against armor.

I wonder how their direct and splash interact with the extra damage dealt due to head shots and back shots.
Combined with the presumed bonus damage to armor this could account for the behavior we're seeing (and really be a factor in overall balance).

Highly doubt we would get some solid numbers, CCP doesn't love numbers as much as I do >.<, my suggestion is that you get a friend go to FW join opposite sides and test it out.

I'm going to see if I can do this with a corp-mate later.

I would be very interested in your results.

1) Bigger hitbox i dont dislike but i'm pretty sure it's a massive pain to code. And i dont see it happening to be honest.
But still, everything has a downside. The point being shield having a smaller downside than armor as it gives, for equivalent tier less HP amount.

Agreed.

Regarding the signature malus on shield. You cant rule it out because the current system isnt perfect. You say most dots come from people spotting the enemy. Yes, most. Not all. And bigger signature could go with longer display on the tacnet, or being spotted from a longer distance. Plenty of choices there.

Most, being the vast, vast majority, like over 90%. It depends on how scanning evolves tbh.

2/3) There i feel you misunderstood me. Like a lot. The whole point, the main idea of my previous reply is to enhance the efficiency of armor oriented suits to use armor modules. And same goes with shield.

Perhaps I did. I don't think racial bonuses are the way to go for it though - perhaps a role bonus would be better?

Regarding base HP of the plates. I merely use a roughly x2 multiplier compared to what shield module gives you at the same tier. So yes, i lowered the std one so it would suit that idea.

I don't really like doing that, because the lower tiered plates would really start to suck when you put on a bigger speed penalty as well. And yes, I know it's mitigated by the bonuses you propose, but remember at the basic level people don't have that SP to invest.

And regarding the penalty, this suggestion only applies with the other suggestion to add specific bonuses to the basic frame skills depending on the race. (copy pasting here)

- Gallente racial bonus : 10% reduction to armor penalties per level. (You would reach 6% penalty for a complex plate.)
- Amarr racial bonus : 5% reduction to armor penalties per level and 5% reduction to heat build up per level (9% penalty)

So in the end, gallente, the most armor oriented suit gets a way lower penalty that it does now (6% for complex) and with more base HP. 6% penalty for 148 HP. How does that make armor tanking worse ?

It makes it worse because you -absolutely must- spec the skills to all 5 before you get to that point. It's not overall worse if you can do that, though.

Regarding ferroplates now. when i said they shouldnt give much armor, it was in the same idea. If a complex ferroscale gives 90 HP without any kind of penalty ? What do you think shield tanker will do ? Both shield and armor tank. And in my opinion, buffing HP with a defense type that isnt originally the suits purpose should either bring you a very limited advantage, or come with a bigger penalty than the specialized suit. eg, minmatar assault using plates. It happens often in EVE.

This is true, but that then effectively nerfs armour tankers because you don't want shield tankers to use it too. You can't balance a module to make it ineffective because otherwise other people will use it. We also don't have that kind of thinking with shield tanking, and it shows. Shield tanked Gallente dropsuits are already on the battlefield.

So yeah, movement penalty would be higher, but only for the race who wouldnt get a penalty reduction through one of their skill bonuses. Is it more clear now ? And again, i also think movement penalty shouldnt impact base movement speed as you cant buff it back.
I must have missed your comment on base movement speed. That makes things make a lot more sense.

You mention something about low level tanking being awfull. yes it is. i'll admit it tend to think at high levels coz that's ultimately where you will end up. But the SP investment isnt that high as you WILL skill into suits pretty quickly, especially when knowing that reaching level 3 only cost an overall 273600 SP. Which would already give 30% penalty reduction.
Aka 6% penalty for enhanced plates using a gallente suit. If this only affects spring and not base movement anymore, then you're way better off than what you get now.

I think a better solution to this would be using role bonuses to mitigate the armour penalties instead. You could also solve the ferroscale issue if you want to make armour tanking reliant on bonuses by bonusing the ferroscale HP.
I don't agree with having to use suit bonuses to make a tank type worth using, because in this case it's only applying to one kind of tank. Shield tankers still don't have to do that, making shield tanking viable on any suit.

To be continued.