5 Player Idea for More Secondary Strategy Card Play

I have only played ti4 twice, once at 3 and another at 4 players. This weekend, we're going to try 5. I dont like the sound of there being 3 inaccessible strategy cards each round. I was thinking of a house rule where everyone still drafts their 1 and a trade token is added to each unused card. On each players first turn, they can add any number of trade goods from their supply to one of the unselected strategy cards. Once the first player in initiative order is back up to play his second round, first the strategy card that has the most trade tokens is activated and everyone has a chance to use the secondary ability, with ties being broken by the speaker. Then, all but one of the trade tokens are removed from that card (note if anyone adds trade goods to a different card and it doesnt end up with the most, those goods stay there for the next draft, increasing the likelihood of it being picked).

Does that sound like an alright house rule? I'd like to keep 5 secondaries in play for each person. I dont like the idea of just having the speaker pick because that gives the speaker even more guaranteed power. This way it's still a bit democratic if people elect to spend resources.

Also for the map, I dont like the look of the recommended setup. I was thinking of just using the hyper lanes or whatever to replace a slice from the recommended 6 player map, but that could lead to mecatol only being accessible via 2 asteroids, 1 gravity rift, and 2 regular planets. Would that be too restrictive?

Thanks!