And the same goes for the slow paced option. Would love to see longer production time needed there, not just slower research.

Fast paced I never play by the way, but of course it has its uses for many. Slow paced, long games on the hugest maps possible is what counts in my book.

Could you have it as a separate pacing. I look at it that slow research with fast building puts an emphasis on units in the game. But slow building and slow research puts emphasis on hero's in the game. It would provide the game with many different play options.

In case you slow down research and production, there should be also reduction in xp gain for heroes, shouldnt it? At least in case you want to keep all the game parts (cities, heroes) in constant relationship...otherwise, with slowed cities and research, the heroes will rule.

My mod uses double production values currently and has 50% reduction on training times. I am still spending 6 turns on a leather and battlehammer unit. I would suggest a production increase as a 1x, 2x, 3x, 5x slider. There is plenty of room in the options screen for such a necessary slider. One of the things I spent hours modding for CIV 5 was slow research and fast unit production. It took forever and all it needed was one simple slider to make the game perfectly to my preference. 

If possible, please, add also accelerated resource mining, gildar and mana income, xp gaining to Fast Pacing to keep game balanced. Epic Pacing is vice versa of course.

+1 to Faster production, and easier than reducing production cost...

A slider for production, like in research ... that would be perfect...That would allow more customization for each game:

want an epic game? NP...Production x1  or maybe even x0.75 ?? really???

Just want a fast game for combating, or testing different weapons/magical items, or a new strategy or...?

NP... Production x3 (or maybe x5 as seanw3 said)

Want a mix-balanced...NP!!!!! Set it at x2.5 (for saying something...)

More sliders are good.

I like fast games where troops matter: i.e. Fast building, Fast training, fast mining, slow research, slow xpt gain.

A slider for hero xpt / unit xpt ratio would be good too.  (It's currently at 2:1, beats me why)