KrystaK, your water sounds very similar to my local tap water, which I use with no "tinkering" in my tanks. My water is typically pH 8-8.2 out of the tap (lowers a bit in my tanks to 7.8-8 as I use a fair bit of bogwood); gH 13/14; kH 11.
My livebearers (Ilyodon xantusi, sourced after Neale's suggestion nearly two years ago) positively thrive, since they became sexually mature around Xmas 2011 they have had regular bi-monthly fry, thankfully each brood is of a managmeable size (max 17, typically ~10, but the females are still growing); the gestation period is a bit longer than more common livebearers; the parents can usually be safely kept even with newborns (especially females, I'm not sure either way if I saw a male eat a newborn several months ago).
Two years ago, when I was new to the hobby, in hindsight I was lucky enough to raise ~10 Pearl Danio youngsters and a bit later 1 of 3 Golden Wonder Killifish fry found amongst the mass of floating plants. Given these are both egg scatterers, I'm not entirely sure how the eggs hatched sucessfully in the Rio240, as I now led to believe (perhaps incorrectly?) that hard water like this should make the egg casing too thick for fry to break free and hatch. At the time I was using a carbon dioxide bubbler for the benefit of my fast growing plants, which did drop the pH to 7.2.-7.4, perhaps this made all the difference.
My Lionhead Cichlid pair challenge my understanding of egg scattering fish even further. Their first and second broods (14/ ~50) hatched in my bogwood laden Rio240, but even more surprisingly the third brood (of unknown real quantity, born in the presence of second brood who ate all but 4 of their sibling before I realised a third brood was even present) were born in my 620T which had virtually no bodwood to alter the water chemistry.
I often think about buying a RO unit and mixing it with some tap water, to get softer more neutral tank water with a lower base level of nitrates (typically 40-50ppm), for the benefit of some of my African riverine fish. Part of me would love see my group of Leopard Bushfish and Rainbow/Pastel Congo Tetra sucessfully produce offsping, while I would love provide my tank bred Beckford Pencilfish with more suitable water and even some sort of fry viable setup with some other softer water species. But like most things in life, it comes down to money, plus right now I know that whenever I need to do a massive water change I can simply fill my buckets with dechlorinated tap water and not worry about maintaining water chemistry stability in the tanks.