For the poll, it is unfortunate that we do not have an "All of the above" option to select.....
Edit.
I did put some thought into this, and boy oh boy can I come up with some ideas for more complex weather control.... Sorry if this isn't entirely scriptable at this time; I'm just throwing out the ideas that came to me in the last couple months.
For the third poll option, "Random Weather Bits", of course I'd definitely like to see improvements to potential seasons as well as weather capabilities. Chronologically speaking, weather/climate would tie in naturally with a calendar/time/temperature system; I would keep the counters for minutes, hours, days, weekday, month, season, year and such, not making the season double as the month, but as a separate counter.
I'd like to be able to specify all the possible weather effects throughout the year, at least four weather effects for each season; and my idea of a time/temperature/weather/overall climate system would divide a year into eighths (at least), each one a season, separate from the declaration of a month. So for me I'd have the four "main" seasons (Spring, Summer, Fall, Winter), but also four additional semi-seasons between, for slightly more gradient control of seasonal effects. Now I know the games that are made are generally meant to be an abstraction, not super-realistic, but I do think more weather potential would increase game immersion at some point. (Believe me, that's not so complex, I started the idea with sixteen seasons, originally.)
Then with the randomization of the current weather effect, take into consideration what month, as well as what time of day, and perhaps even temperature for that time of day.
Most of this is not so do-able without more complex note-tagging in place; it would be nice if we could specify if a map has a minimum temperature, maximum temperature, mean temperature, specific climate/weather always allowed, specific climate/weather never allowed, et cetera. So a desert map would more-or-less mostly be steamy hot with random chance of dust storms; a tundra or sub-arctic map would have lots of cold temps and frequent snow storms.
And there is even more potential for linking weather effects to skill or item use; say a battle occurs within a town map on a summer day; if a wintery or snowy effect were used to fight and freeze an enemy, it might be nice to have the snowy effect still active, but dissipate to the map's median temperature.
Again, so much of this might not be so possible with the way the RPG Maker editor is, at this version; perhaps it's something I can work on in my own attempt to develop an alternative game-maker editor/engine.