I would look into whatever shenanigans the "smart" alternator may try to pull off, if that's what you have. There may be some subtleties there beyond the mere capacity to do it. May not be an issue (I have no idea), but I'd check, just to be safe.
Should be a temperature compensating alternator on the 200, not a smart alternator.
Plenty of folks run a 25A, 30A or even 50A DC-DC converter on the 200 without issue. But unless you need the fast charge rates I would recommend the lower powered chargers as there are other things to consider when running the higher powered ones (heat dissipation, large wire size and price to name a few).
IMO, Yes. Neither the two values are relevant.
RedArc, hampered by potential liability, derived their 'charts' for this sort of thing specifically for US sales. (maybe NZ too lol)
Apart from extreme and relatively brief situations, your alternator will otherwise never output 180 amps constantly, just like the 40A BCDC will never output 40A constantly. Both have the capacity to do so, but it's an exception rather than the rule when they do.