The standard is better more stable the v2 will get deprecated soon.
Nope, you can change the currency for your entire Account under Account > Profile, and for each funnel under Funnel > Settings to any currency you want.
Nope, the same as above, just change your currency under Funnel > Settings (in Funnelish).
Cycle Type can be Weeks, Days, Months or Years, along with Cycle, you can control how often you want to charge your customers, even if it’s infinite that’s not enough you should specify how often per month or per year or per day…etc. In other words how long each billing is apart from the other.