I agree with your changes for the Shopper scheme, except for the mine fuse. It should still be random, otherwise whoever starts playing first will be able to make use of most of the mines, thus gaining this advantage of which the other players won't have later. If random, they'll think twice before risking touching any.
Oh, and another change needed for HB Shopper IMO is that the weapon retreat should be 5 seconds instead of 3 since there are also ground weapons to be used, and the spread from 3 to 10 seconds, when you can even get away with rope so much faster… having 5 seconds to get away on ground is the least you can do to make it more even. Adding more time than 5 seconds wouldn’t be interesting since you likely wouldn’t have much ground to retreat, and it’d be too much of a monotonous and non-dynamic retreat to wait for as far as the game works.
I also enjoy having Uzi and Skunk in crates in Shopper for more variety, but I wouldn’t mind not having them in Shopper. I know Skunk might generate more confusion in who’s leader because of the poison effect.
I’d also like to emphasize how important I think infinite Bazooka is in Shopper. I also always get baffled whenever I see a Shopper scheme made for a tournament, for example, in which there is no infinite Bazooka. It’s like, you have no standard weapon to do reasonable damage if you are unlucky, finding some very weak and ineffective weapon, so it turns out you end up with some dead turns during the matches. With infinite Bazooka, on the other hand, you have something to at least keep you steady in the killing race instead of just being helpless and letting your opponent crush you with a bigger weapon, allowing unnecessary luck to interfere in the game/scheme. Moreover, it allows you to choose whether to use the weapon you found in the crate or Bazooka according to the situation, providing more strategy in play.
The 40 seconds in big rr... I wouldn't see a problem if most Big RRs were played with Rubberworm's /ldet, which is how traditional Big RRs should be played so that all players are allowed to have the same turn time and not lose a game for having had unlucky turns in which make the timer stop (as in any real race). And this is how weaker players manage to beat stronger ones. The fact that one type of fall makes the timer end and another doesn't doesn't justify at all why that should be true; it’s basically just a technical limitation that has a fix. Plus, if you feel like speeding up your pacing, you are already risking falling more often, and hence giving your opponent more chances to catch up. Over the years, I lost count how many times I won a Big RR lamely just because my opponent, who was better, had bl in a few turns. Now I know one can say that falling isn't affected by luck in Big RR since it all comes down to the commands you insert with your fingers, but the fact of a player earning so much more time to outrun his opponent in the race (as a time bonus) is just plain stupid. It can even make the player who is winning slow their pace down just so they can rope safer since the time bonus already granted certain victory to some extent.
Another reason that makes /ldet more enjoyable is that it allows players to rope faster than their usual pace if they are seeking to improve their speed. If you try to do this in a game without /ldet, you are just likely to make your turn end, and then you’d just have to sit and watch the other players race instead of the game having let you play within your turn time limit. And of course, that also leads to a slower improvement from the players.
But since most players don't have rubber, what I tend to do is hosting with 35 seconds and no banana, and here's why: traditional Big RR is 30 secs + 10 secs of banana, so you'd initially think you have 40 seconds, but that's not entirely true. The extra 10 seconds you have won't allow you to keep racing if you fall from rope, so those are some “semi-10 seconds”, which is why I put that very in-between number, 35. And another reason for it is that having 40 seconds under a race scheme settings that might make you lose your turn from the very beginning is just way too much of a time bonus that you might give to your opponent(s). With 35 seconds, however, you won't race as little as you would with only 30 seconds, and you also wouldn't lose that much time if you fall, so the advantage you'd give to your opponent wouldn't be that huge.
What do you mean “no teleport in Big RR”, Sensei? There isn’t teleport already, unless you’re talking about the auto/manual initial placements option?