The (small) difference here is both the range and design of sunfire as an optional item. I actually wouldn't be averted to seeing Sunfire not damage units unless you damaged them within a time window. The issue is brought up with such urgency for Blitcrank due to two things, however: his nature as commonly a support who's more likely to be warding in this method (rather than blues or sweepers in the current meta, especially) and the fact that as a strong tool, his ult itself, a skill that he's (by technicality) required to get causes this problem. Within the first 10 minutes of the game, it's possible for warding dragon to be a problem depending on how lane goes.
In jungle-passing situations, Blitz's ult passive can pull from some pretty inopportune ranges (and this is specifically reiterating an example I saw where trying to back in the bush, Blitz's passive pulled red and got him killed when the enemy he had juked saw it move). With a sunfire, unless you went to hug the VERY edge of that bush and aggro'd one of the minis, you likely wouldn't pull the camp like that. Sunfire does have the problem of making you apparent in tight corridors, revealing you in bushes if someone steps too close, or breaking non-combat effects if you just run too close to something. Blitz's passive shares this, and yes, I think they should botj be dusted off and chiseled a bit.
Sunfire wouldn't lose any of its effective power if, once again excluding champions preferably (or including them only if the enemy champion has no vision of the cape/passive user?), it didn't tick damage on something until it was in combat. This would also mean that attacking one minion should allow the whole wave to be damaged, since the 'call-to-help' should cause them to enter combat if they're not already in combat with other minions.
Please, help me refine the concept or bring up an alternate one. Even thinking of ways this could function in an ideal environment is better than lounging around (although bringing up sunfire is already a huge bonus to this thread, kudos to you sir!). With the way this is going, we could probably at least peace together some kind of vision of what, in total, we'd hope the end result could be so that those who view this thread (reds or even normal forum-goers) get a clear image of what we mean.
Thanks again for reading, everyone who let me waste a portion of their life!
EDIT: And yes, PLEASE correct anything I got wrong. I want this to be an informational debate trying to dig down to the nitty gritty, no a biased argument where we attack each other.
[slayer-jinx-catface]