I would say another equipment slot + a cpu/pg boost + a buff to move/sprint speed is what scouts need.

Why?

An extra equipment slot would allow me to do more scout-y things at once, like uplink + scanner or uplink + stealth (once it gets here)

The cpu/pg boost would be so that I could actually fit this new equipment on my already cpu/pg tight suit

The move/sprint speed boost would help move the scout away from being a weak assault. 0.5-0.6 m/s difference between our assault variants isn't much to talk about.
Edit: I'm not sure how much of a buff we need for speed, but it needs to be enough so that the two slowest scouts (Caldari and Amarr) are still quite a bit faster than any other suit's base speed.

In addition to what I said above, I'm slightly against adding more highs and lows to scouts (I'd take it just because CCP needs to throw scouts a bone though).

The reason is because at the moment there are no useful modules for scouting. What about the ones that affect passive scan? Even if passive scan actually worked, for most scout-related roles they aren't very useful. The precision enhancers? Only really useful to a scout for finding another scout. The profile dampener? Only useful for a scout hiding from a scout hunter. Range amplifier? Perhaps a cqc scout would find it useful (Would need a minja or shoty scout's POV on this). All of these (except the cqc scout) are highly specialized fits. What about codebreakers then? While I do find they are helpful, the extra hacking speed provided by them rarely feels necessary. I feel most scouts probably wouldn't see much use in adding these modules.

What would these new slots go to then? Adding more tank or more gank. While that is good for scout survivability, it would also would further encourage scouts to play like speedy assaults which I do not believe is what CCP intended for the scout.

Give a headshot bonus to the gal, (we can now see back gal scout sniper and with pistol)

These are the stats for a minmatar scout and minmatar assault both with same shotgun and both with 2 enhanced kinetic catalyzers, with the rest of their resources sunk into shields. Against a non-CQC character, do you think the 9.09 sprint vs the 8.52 sprint is going to matter as much as the 148hp bonus on an assault suit over a scout suit?

While I don't necessarily think that scouts should get a movement speed upgrade or that other suits should be slowed down, I don't think the scout's benefits matter very much compared to them being made of paper; if a scout doesn't have enough health to survive any shots it doesn't matter what they're good at, because there isn't realistically a role for "not getting shot" as a scout. Run and hide is a great role scouts should fill but at the moment I feel that either scouts are too weak or weapons are too strong to make it a viable tactic: if you have to run it's already too late for most scouts.