I used to brew beer when I was single. Not really too much science. Just required learning and repetition of steps done correctly to get a good smell/flavor/taste. The science comes in when you want to get tricky with combos and flavors, or try to brew when you are drunk. Sticking to a recipe is easy. I used 5 gal carboys and did a partial mash. I also used to put my brew in a soda type keg and charge it with Co2, all three "kegs" kept in a big enough cheap fridge, and run it thru the door (sealed up so no fridge air would leak) to a tap, instead of bottling. Much easier bottling and drinking process to me. Good way to go if your brew is not going to sit for a long period of time.
As far as opening up my own brew shop, that requires too much capital IMO. Might as well open up an unestablished restaurant. Both have high failure rates. Not trying to get you down either. Dream big and big things will happen. Are you planning on doing this out of your home? If not, then you'll need capital for building, renovations, supplies, storefront furniture, paying liquor license fees (at least here in OK to be able to sell beer you gotta pay these), possible zoning issues to deal with, etc.
Then, people brewing their own beer. Not that it is a dangerous activity, but liability insurance prolly isn't cheap since they would be in your store working with boiling water and big glass carboys. Then you have to worry about sanitation more so than other food/beverage retail places. Sanitaton is the key to home brewing.
And then you get into other retail variables. Like: location, location, location. Is there a market for this store in your planned sale area/town/city? Will you have competitors? How are you going to promote this venture (promotion/advertising takes capital too)? Etc, etc, etc.
Definately do your homework is all I can say.
This site may help you:
http://www.abcsmallbiz.com/index.html
PS - I didn't vote in your poll cause you didn't have an option for: "Used to brew when I was single" choice