With the basement, if not a lot of people have seen the basement, or maybe just didn't really pay much attention to it, you could consider building a false wall straight from one side of the basement to another and just making the basement appear smaller and a portion of it disappear. Just an idea. As for the garage, there are plenty of wireless security implements that are sold now a days that can be bought separate and connected to a wireless keypad (much like any regular wired system) like motion detectors, window and door breaks, loud siren alarms, broken glass detectors, and they all report to the keypad. In some of the security devices I viewed the keypad can be programmed with up to 5 wireless phone numbers that the unit will call if it gets tripped. This way you can be notified even if you aren't at home when the alarm is tripped. It's pretty cool.
I was surprised to find that my 400 watt H.I.D. didn't really up my electric bill (along with an inline fan, some oscillating fans, and other small devices) much more than $20 to $50 a month, depending on the light cycle. But I run the T5 that I showed you and the 400 watt, so, it can get up to $50 more. However, you're right about the CFL's are a pretty good option, and the LED lights are expensive, but even more of a light bill saver.
Don't get too big with the room and a 4" inline fan will work great (at about 190 to 220 cfm) to replace the air in the room at least 4 times an hour. The carbon filter for any 4" fan can be found for less than $50. I work with Fox Farms Happy Frog potting soil because it already has such great nutrients loaded in it, you don't need a killer amount of chemicals to boost your plants. As a matter of fact, I find that the Organic nutrients are a bit cheaper than the chemical ones anyhow. I started with Hesi, but it was really overkill and contradictory to using a organic soil, so I've switched to General Hydroponics. Good nutrients and I don't have to worry about the pH balance being thrown off in the soil. Temperature and humidity will always challenge you at some point in time or another with climate change during the seasons if you live in a seasonal location. I'm pretty sure with how humid the summers get in MI that I'll need a dehumidifier at some point, or an A/C unit.
I think you can pull this off. If I can suggest anything it would be keep it to 2 to 4 plants to start. My 3'x3'x7' tent is packed with 4 plants, but using bag seeds you need to start by planting no less than 4 seeds just in case you don't get but 1 female. If that happens, just hurry up and plant another few and keep your plant in a veg state a bit longer and let the other catch up. That just another idea. You'll know after the first run or two if you want to continue or you're any good at this. It's not for everybody, but I think just about anyone can learn how to do it. Best of luck!
I'm about to shut my room down for the night/day, so I gotta run. Good luck, plan well, and keep records of when you make changes to your operation. Records will help you a lot in the long run. Whatever you do, don't be afraid to ask more questions, no matter how big or small the question.