I think the MSU strategy with Saurus is very interesting and certainly viable. However, its important not to overestimate your troops. Yes, they're really nasty in combat for basic infantry, but expecting them to hold their own against Clanrat blocks is unrealistic. 5 Saurus will hit on 4s, wound on 3s, with a 5+ save to the rats. True, you probably wont lose any to attacks back, but that's not enough to break the static 5 CR especially since I assume you're not bringing a banner with the smaller units.
I don't mean to make you sound uninformed, but I just thought I would check since you are a Skaven not LM player, take no offence. You know saurus have 2 attacks each and the vast majority of people take spears? A unit of 12 saurus (thats a rank, so you have 4 static CR not 5 too btw) will get, when charged, 24 s4 attacks. Assuming 4 die to shooting, that gets rid of the rank but still gives 16 s4 attacks.
Flanking skinks may not be as outrageous as they first seem. Certainly they will offer a few easy kills for the rats, but you're stripping them of ALL their power. You'll knock out our rank bonus, giving you a +1 for flanking and Clanrats -3 rank bonus. Skinks squish easily, but I don't think my rats could kill 4 of them. As an extra bonus, the leadership bonus doesn't apply to Skaven if they are flanked, so our leadership goes from 8-10 (w/ general) down to 5-7.
Flanking with skink skirmishers = bad, flanking with ranked skinks = very good, and yes even better against Skaven. Flank charges are the key big weakness of Skaven.
Someone had also mentioned Chameleon skinks earlier. I'm not familiar with how that unit works exactly. I assume they are Scouting Skirmishers but do they have any extra advantages outside of that? They could potentially make outstanding Jezzail hunters. 7th ed. Jezzails are no longer Skirmishers so if you jump outside of their frontal arc of sight they wont be able to shoot at you!
Scout, higher BS, -1 to hit them at all times.
I promise you that any Skaven general worth his whiskers will blast Cold One Cav to bits. Skirmisher screens will not work I'm afraid. The Warp-Lightning cannon alone fires like a normal cannon-ball now so you can guess the range. At the end of the "bounce" a small template is placed to represent an explosion and NO armor saves are allowed regardless of the strength on the shot. Jezzails on a hill would also make short work of these units. A seer on a Bell is considered a large target for casting Warp-Lightning (and all other spells). Lastly, one of our new spells Scorch lets up "place a small blast template anywhere within 24" doing str5 hits to anything touching it, no partials. My understanding is that Cold One Cav units are very expensive and generally have a hero and a standard to give them extra punch. You're typically going to lose a lot of victory points this way.
Are warp lightning cannons popular? I haven't faced one in ages. Certainly heavy cavalry are a primary target, my Dragon Princes never seem to have trouble reaching combat intact though.