You're very welcome 3 - I'm happy to share any knowledge and help you out in any way that I can. I started out on here too, and have learned more than I ever thought I could from the RIU forums!
pH
It sounds like you'll want to bring your pH level down a bit more. I don't have a meter for my grows but I use the fish-tank water test kit for mine where you take a sample and put in the special solution, then shake it up and look for a yellowish result to know I'm in the 6.0 range. Most info on this will advise you to stay around the 5.8 pH mark as this is will allow for optimal uptake of nutrients - but that becomes more important of course once you start feeding them. At this point you don't need to use any nutrients - wait until they're about 3 weeks old before starting them on any nutes, especially in soil - hydro setups are more finicky as they rely on the water quality right from when there's a tap root started. If you have a pH tester, you'll want to check the water pH before using it each time to make sure it's in the 5.7 to 6.2-ish range - your plants will thank you for it by staying nice and green!
Lighting cycle
For lighting, I've had great success with just staying with 24 hr light for the veg cycle. If your power-bill is a concern then you can change that to 18/6 (on/off) but this means you'll need to ensure you have a light-tight veg area so your dark cycle is COMPLETELY dark. If you're using the same grow area for flowering, you'll be needing to have that setup later on anyway so in that case 18/6 shouldn't be a problem.. I've done it both ways but for me it's a hassle to use the 18/6 in veg because my 'veg chamber' is my spare bathroom tub!...lol. I have a 400w MH light hanging from the shower-curtain rod positioned right over the white tub in order to get the benefits of the white reflective walls and the convenience of my smaller pots to drain excess water easily. Initially I had that bathroom 'light-tight' and ran an 18/6 cycle, but then we couldn't use the bathroom during certain times of the day which became annoying...lol.
Plant height - veg to flower
As far as space (height) goes, I've let mine go as much as 12 inches tall before moving them to flower. It can take as little as 4 weeks to reach that height or as much as 6-8 weeks for some strains and/or growing conditions. I haven't really noticed that 24 hrs of light in veg makes that much of a difference in how long it takes to veg to that height - but that's how mine have grown with my setup. The bathroom veg area doesn't get much fresh-air in, so that could attribute some slower growth for that cycle as well. I've seen some growers on here that are consistently ready to move from veg to flower after 4 weeks or as little as 3 weeks - these cases are most of the time due to starting from clones though. Starting from seed takes a bit longer but you do end up with a stronger plant in the end. The strains I've grown have sometimes even started to show sex at the 4-5 week mark which makes it more tempting to put them into flower, but keep in mind that your plants WILL double in size during the first 2-3 weeks of flowering, so if you have a height restriction, you'll want to consider how big your flowering pots are plus the veg size of your plant and then add another amount of the plant size to gauge when to move into flowering.
Water
For watering, the best method I've found for veg (in soil) is to keep an eye on the weight of the pots. You can tell if you need to water more by how heavy the pot is. Lift it up after you do your watering and then check the weight each day to determine if you need to give more water. If you see leaves starting to droop, don't worry - that could be a sign of either under OR over-watering. Go by the weight - lift the pot when you know it's dry to get a feel for how heavy it is with just the dry soil and then again after you water to compare. I have a small fan blowing across my plant tops which consequently dries out the top inch or so of soil in my pots - this is great to build your plant strength and will build thicker stems that they'll need later on when you have heavy buds to support - but again, lift the pots every few days to determine if they need more water yet or not. Some strains actually 'like' to dry out good before getting more water. Remember, too much water is more often worse than too little - if you water during veg more often than once every 3 days, you're likely to be (a) watering too much, (b) not using enough perlite in your soil (to retain moisture).
pH adjust
As for adjusting pH on the 'cheap'... well there are a few ways to do that - I've seen a few posts on this site with some suggestions... but because it's a fairly important thing, I'd just visit your local gardening shop and get a small container of pH down. It's only about 5-6 dollars for the small containers and it's vital to your grow. From the sound of it, you have fairly 'alkaline' water so you shouldn't have to get any of the pH up solution, just adjust it down to 5.8 and if you happen to go too low, just add more water. I've found that if I leave my 'tap water' sit out for about a day, it burns off a lot of the crap in the water and is then easier to adjust and may even come down a bit from 7.0 to 6.8ish in a day.
I have to say - I really enjoy being able to share this information with you - it actually helps remind me of some things that I sometimes take 'for granted' in my grows since starting. Sometimes it's the simple things that you don't address and fixing these issues early on can pay in dividends later on in the grow. Please feel free to keep asking any questions you have and I'll do my best to help out or point you in the right direction!
Cheers and happy growing!