Interesting perspetives, thanks for sharing! Funny you mention Silicon Knights, when they were still around at one point I lived pretty close to their HQ. Rare to see someone reference them!
TBH, in game jams I was up against a lot of web based games, So it's not a performance issue as much as literally a filesize and format issue. Folks much prefer browser based, I guess.
Next patch (v0.0.2) will keep the standard battle system but I'm strongly leaning towards trying something more real-time like ATB/CTB - add some depth to different things like summon spells taking longer etc.