I don't have beardies but I think I prefer the ones with more depth of colours like yellow. I guess it is a "Do you prefer blondes or brunettes?"
question. They are all great if you like beardies.
That is a matter of personal preference. Most people say 10-12 hours but I have mine about 17 hours, which is about the maximum as plants need a rest period. There is a good place in Christchurch to buy tubes. Send me a Pm if you want details.
They are probably the original bulbs that came with the tank. I think to replace them at the pet shop would not be cheap but if you can get them from an electrial wholesaler would be a lot better. Many people like to use daylight but I use 10000k and 4000k (growlux and cool white). You will probably find that new tubes will make your plant grow better. When the tubes are old they get dark at the ends.
The T8 means it is a tube shape 8/8th inches in diameter (a one inch tube rather than the thinner 5/8 th inch tubes. After the T8 there is often another number e.g. T840 which would mean it is a one inch diameter tube of 40000K or cool white. They don't all have that.
They sound like they both could be about 10000K which would make them a growlux type tube for growing plants. That could be confimed by the numbers on the tube.
Everyone has their own way but I found they did best if the males and females were seperated and conditioned for a couple of weeks then spawned for a week but you need to do what works for you. Many people are put off by the time you have to store the eggs but if you get organized in a few months you can have heaps of them and more coming. They are the original instant fish.
Looks like Bacopa caroliniana aka giant Bacopa. There are two varieties in NZ. One is hairy and the other not. I don't grow either. I think the bald one is the easiest to convert to submersed (they are usually grown emersed--hence the flowers)
You are generally looking at storing the eggs of Nothos for 12-16 weeks at about 22-25 deg C. and rewetting them every month as only a percentage hatches each time. Nice fish but like all Nothos need salt to keep the velvet away. Anuals and live longer at lower temperatures.