My army list is as follows: Skink Priest Skink Priest (Plaque of Tepok/Diadem of Power) 18 Saurus, Spears, Full Command 18 Saurus, Spears, Full Command 10 Skink skirmishers, Blowpipes Salamander, Extra Handler I have two options 1. Use Plaque of Tepok and have an 11 strong skink unit 2. Use Diadem of Power, and have a 10 strong Skink unit What is your opinion? it's 800 points, by the way.
What do you hope to achieve by having 2 priests? Give Tepok to the lvl 2 and skip the second priest imo. I personally find spears to be rather useless but you might be limited by what models you have. Not sure if 2x18 or one big block of 30 SWs is the best option but you can always try both. You could use more chaff, like a second skink unit, a salamander or some cammos. Diadem is a very defensive choice as its going to kill your own magic phase, making it a great choice if you take a single lvl 1 just to dispel, but I'm assuming you want to be offensive with your magic so Tepok is way better for that purpose.
Normally, it's my Saurus that take the charge, and with their In. 1, go last. With spears, I'd get 25 attacks back unless more than 6 are killed in CC. The two wizards gives me three spells, and a better chance of killing any Hexwraiths that turn up, and forces the enemy to spread their shooting. I also get 1/3 chance to channel. However, with one level 2 priest with diadem and plaque of tepok, gives me three spells and magic defence easily good enough for 800 points, for five points cheaper. Also, I think two units of 18 saurus gives me more flexibility.
In which case, I'll have two skink priests. One at level 2, the other level 1. I need two to kill ethereals - and again it gives me +2 to dispel and 1/3 chance of chanelling. That's 180 points for both. Here is my new list: Skink Priest, Level 2 Skink Priest, Plaque of Tepok 20 Saurus Warriors, Spears, Full Command 15 Skink Skirmishers, Blowpipes 3 Kroxigor 1 Salamander, Extra Handler Kroxigor is for fast support. The Saurus can maarch forward and take most charges on the front. The Skinks and salamander on the flanks to cause trouble. The priests stay back, use magic, and hope there are no scouts or flyers about (though I have Lore of Heavens to deal with flying units). What do you think?
ScarVet with a magical weapon would be a far more reliable anti-ethereal option. That extra priest will channel 1 power dice and 1 dispel dice per game on average, so you are paying a lot of pts for 1 PD & 1 DD (and 1 spell). Its cheaper to just get a power stone, it adds more dice on average and you can control when you want them. 1 priest is enough magic offence and defence for 800 pts, but if you really want to go the 2 priest route then your current set up is probably the best. Your new list seems more well rounded and fun to play, it has a little of everything and is still fairly competitive.
No, definitely nothing major. Skink skirmishers are normally played in 10-12 units but I play 3x16 myself so I know from experience that large skirmish units are perfectly fine.