Maybe think about more blessings. they're so versatile and Lem can do a lot with them. Then maybe spells, especially Holy Light and the better Arcane attack spells. Cure of course and if you have blessings in hand and a largish discard, maybe don't try and recharge Cure and just swap it back into your hand and use it again.
Most importantly, you should play the way that seems most fun for you.
Firstly, I would suggest going Dex before Char, because winning combat is more important than recharging your spells - especially since Lem has the "discard a card to get a card" ability.
Secondly I would reccomend pumping up your spells and allies. Spells are very versatile, and with no one to compete with for them you can take any you find. 2 Cures, 2 Hastes, and 2 Incendiary Clouds should be perfect for being almost invincible. And on allies the Black Arrow Ranger is just fantastic for Lem (but he is AP 4). You can use the Cat to help with recharges until you get your Char up if you follow my advice and capitalize on Dex.
For our RoRL playthrough Lem focused on Dex until it was maxed before he started on Charisma. Our RoRL had a crossbow to handle most combat checks. He generally only had one attack spell and, like Orbis says, more often than not you don't care if your spells recharge anyway. Often you don't even TRY to recharge because it's more convenient to grab Cure back out of your pile. Our Lem had a Cat too, but it almost never got used as anything but +d4 fodder.
It's actually taken a bit of getting used to in S&S, where Lem can't swap out his cards willy-nilly. I'm basically recharging a card for a d4 every time I try to recharge cure. I did the same thing with Seelah's add a d6 when I started playing her after playing through the whole game with Seoni. I basically had to take a minute and think "wait, you have to TRY to recharge these things?"