First of all the 'Radiant Collection' gacha doesn't end it juist gets more stuff added to it periodically form past limited banners. As such UMP9's valentine costume will always be available from this. As for FAL, and all other costumes, some will be added into the radiant collection. If the batch of skins included a Live2D (like the wedding dress set) none of skins in this batch will be added to radiant collection, if there was no Live2D the batch will be added at some point generally a couple months after their original gacha. Also all skins are added to the black card exchange in which you trade black cards (received upon gaining a duplicate of a skin you already own) form skins at varying prices (this includes the Live2D skins)
Also note that occasionally a gacha banner will be rerun like later this month (I speculate that this may be the wedding dress's due to the similarly themed special store event).
In terms of acquiring tokens they are only available by completing certain daily and weekly quests. You can earn 5 daily (win battles, combat sims, T-Doll production, Equipment Production and repair T-dolls), then a further 5 weekly (Boss kills, Skill training, and 100 S rank battles). This comes to total of 40 tokens/week which is equivalent to 4 limited gacha pulls or 6 radiant collection pulls
Hope this helps