Using Death Blossom like a howitzer is very interesting and it never occurred to me. I've always considered it to be a lame spell that will probably hurt yourself more than the opponent. I will have to try it out in MM7 when I get it. It's true that when I was battling goblins near that fort in Harmondale, I found that the "cannons" were firing some Death Blossoms (among other spells), and it did clear the goblins up very well (except when they were right next to the cannon).
In MM7, I had a good fight when I was traveling to Deyja by foot, and I had some... let's say disagreements with a guy that wanted me to pay "Necromancer Tax". I refused, so one group of zombies emerged in front of me and another group behind. Three of my characters were hacking and slashing at the group in front while the sorcerer was casting fireballs behind, and when the group behind came too close, the group in front was already a bit thin, so I could run right through them and finish them all with another fireball and a couple more swings.
I also managed to do some stealing. Most notably, I was unwilling to pay 500 coins for the lute on Emerald Island, so I just stole it . (I'm also wondering if I could refuse Malwick and steal the wand from him .)
As for Celeste, I thought I heard some NPC saying that wizards live in there, but I'm not sure. Maybe they only said that the wizards built a teleporter there. Anyway, it looks like I will do other things now and try again later.