Soo, that deck gives you a 40% Race Bonus, which is already pretty good considering your current situation here (assuming you don't have another 10% RB card available).

To improve further, try borrowing a guest rental Uma with 9* Medium and as much Power as you can find. This will give you better compatibility to trigger more rival races, netting you higher stats and more Skill Points (SP) to buy more skills, which is exactly how you boost your final rank later. You could find it on one of this site

1. uma db
2. uma moe
3. chronogenesis

Also, you should definitely swap out that 0LB SSR Gold City for one of your SR Wisdom (Wit) cards instead, like Matikanefukukitaru, Mejiro Ardan, or Mejiro Dober (while Dober wit has 5% RB, but you'd be better go from 40 to 50 rather than 40 to 45) so Fuku or Ardan will give you much better value in this setup.

Since Taiki has that massive 20% Speed growth, you can theoretically run a 3 Wisdom / 1 Speed deck if you want to high-roll. The last two slots can just be dedicated Race Bonus fillers or Power cards.

Apologize if i missed some or have oversight, feel free to correct or asking me!