I played through on the Balanced difficulty level and I really wish I had done Tactician because I was breezing through basically all the fights. But also I have a LOT of experience in the system, so I've got a good idea about what is optimal.
I've heard friends who had difficulty with the combat. If that's the case, I think it's reasonable to put it down to the easier mode. There's no shame in it. D&D combat can be very punishing if you don't know what to look for. And there's a ton of class abilities to keep track of for new players.
A couple of recommendations: rebind the "view interactive objects" key to something like E. You're gonna use it a ton and having in Left Alt is weird to me.
Make sure you prioritize maxing your casting/combat stat. That means intentionally dumping stats unrelated to them. Personally I recommend using Withers to respec your party members to get their stats better. Shadowheart does not need a 13 strength. Clerics, after the first couple of levels, basically never attack with their weapons, they should use Sacred Flame or Produce Flame. Those points can give you more CON (for health) and DEX (for AC). Personally I recommend against getting feats at level 4 and instead getting an ability score increase for this reason.
Also try to get spells or abilities that you can use as bonus actions. The best turns are ones where you use your action and bonus action.
Try to limit the amount of concentration spells on your spellcasters. You can only have one up at a time! So focus on just a handful and have the rest be non-concentration.
If you know a fight is coming up, you can enter turn-based mode early and get a couple of attacks or spells in before initiative starts. Generally it starts when you get in their line of sight (hold shift to see that).
