Sunflower - direct sow about a week after last frost, placing seed about 1" deep.

Acer rubrum , sow at once upon ripening, or soak, then sow approx 9 weeks at 39F (stratify, a period of moist cold), then move stratified seeds to 70F for germination

Wisteria from seed can take more than 10 years to bloom if you were wanting a blooming bonsai, seed grown wisteria is typically used only in grafting for root stock. Sow about 3/4" deep at 65-70F, should germinate in 30-60 days.

Prunus x yedoensis (Yoshino Cherry):
2 - 3 months cold stratification and is best sown as soon as it is ripe. Sow in a cold frame as early in the year as possible. The seed can be slow, sometimes taking multiple cycles of fluctuating temperatures, 18 months to germinate.

Ok so what method should i use to stratify/germinate?
Is there any way to speed up the stratification/ germination period for the Punus x yedoensis?

This time of year, I would sow the seed, wrap the pot with saran wrap and secure with a rubber band or put the pot in a zip lock bag, and put it in the refrigerator. If space is at a premium, you can put the seed in a small amount of sterile moist sand or sterile moist vermiculite, just a couple of teaspoons is often enough, in a small zip lock and refrigerate that. Later in the year, I would put the pots outside rather than refrigerate, my winters will often average to about 40F.

And no, there is not a good way to shorten the period needed to stratify. If the periods provided that are needed to break dormancy are too brief, you may have to begin again and lose time.