What's the plan with switching from Angel's Grace and
Dawn Charm to the counters? I feel like counters on the scepter are a bit more leaky than
fog affects? (i.e. there's more room for the opponent to get through, you'd need
Curse of Exhaustion AND a Scepter WITH
Mana Leak to be fool proof, whereas the
fog effects make you vulnerable to only burn, and 20 dmg with just burn is very hard to do.) I like the addition of the counters as a way to
protect the scepter, but I'm not sure if they're just scepterable themselves. Have you done much playtesting with either version?
You're sort of switching archetypes from more Turbo-
Fog oriented to more American Control. I'd recommend that you read up on both of those (see if you can find 'primers') I think that the
Isochron Scepter fits better with the fogging, I could be wrong, but I feel like a well constructed control deck would get more mileage out of
Snapcaster Mage and card draw than the scepter (which takes a bit more to get online.) The nice thing that the Scpeter does in a Turbo-
Fog deck is opens up
fog slots to run some control cards.
If you're going with the addition of red,
Electrolyze is very popular in American Control, it can get rid of potentially two creatures, and replaces itself in hand (a 2-for-0!) Don't underestimate the power of
Lightning Bolt or
Lightning Helix as cheap removal (helix preferred with Scepter; you're paying 2 anyway, Bolt preferred with Snappy, you can flashback a turn earlier)
Anyway, read primers on American Control and Turbo
Fog in Modern and that should help you decide where you want to take this deck.
PS- If you do want to keep this Modern,
Sol Ring (in your maybe board) is not format legal.