1) I'd suggest either upper/lower split or Total body at this point. I'm very partial to the upper/lower split personally. As Addiction said, it's something you have to try yourself and see--thing about this iron game is that there's NO WAY to get around trial and error and experimentation. NONE. PERIOD.
You can ask big dudes how they got that way, you can ask authors, you can read studies, but ultimately it comes down to doing it yourself. Those people can help give you ideas to try, but ultimately it comes down to trying it out yourself. the most important point is: [b] FIND SOMETHING AND STICK WITH IT![/b]. Don't flit from program to program every 2 weeks. Give a program at least 6-8 weeks of hard-ass effort (and lots of food) to assess whether it works.
2) Not really. Spinach is really good. Well, fresh baby spinach anyway. You may get to like it more than lettuce. It's more packed with vitamins anyway. Eat BIG, eat OFTEN, eat PROTEIN. I started out just about where you are now. (6 ft, 160). Eating is the hardest thing to keep up with, but it pays off.
Thing is, it can't be "eat really well for 3 days, then forget your meals for 3 more". It's got to be consistent. Aim for 5-6 meals a day. Keep it simple--protein, healthy veggies/carbs/fats, frequent meals. Don't sweat details!!! Guys like you and me, who've been skinny and tall most of their lives, gotta eat the farm. DON'T be too worried about carbs, or whatever, just eat lots of dead animal. First and foremost, if the scale is not moving up, you're not eating enough. Period.
In a way, it's a blessing you don't have a way to portion your meals--it will force you to simply eat w/o being anal about specific #'s in mind. Aim for 1-2 lb gain a week (always measure in the morning on an empty stomach/bowel). Eating big isn't about getting hung up on specific #s--"Oh I ate 4000 calories but I'm not growing". The answer is eat more!
3) Actually, there's two requirements--lower your bf% and have muscle to show. It won't matter if you're at 3% bf if you're 130 lbs. Frankly, if you really want to make the quickest progress, toss the notion of a 6 pack out the window for the next year. I'm serious---it doesn't mean get fat!... it just means you won't get a 6 pack. Exercises aren't a matter so much of "ab exercises" as much as overall muscularity.
4) Years. Measure in years. I've said it once, I've said it 1000 times--this game is a LONG-TERM game, measured in years or decades. It took me 7 years to go from 160-240, at roughly the same body fat. Do the math. If I hadn't made a number of retarded mistakes when I was early into training, it could have been sooner. But the big thing is, plan for the long term. This is a life style, not a hobby.
Doesn't mean you can't go out, have fun, have a life, eat pizza, and stay up all night, go to parties. I did plenty of that. Enjoy your life! However, it just means you can't half-ass it for 6 months and expect to be hyooge. Don't miss meals, don't miss training sessions, don't half ass your training sessions, don't binge drink 4 nights a week. Get good sleep most of the time. Or if you can't, eat extra to make up for lost sleep :). I figure if I'd have applied myself a bit better to eating I could have made it in say...6. Maybe 5. Training hard wasn't an issue for me personally. Gains come quicker early on and less quickly later.
Hope this helps. This is what I've personally found through my experience. Good luck, I'll be waiting to see your progress in a year. Keep grinding on through the plateaus and the hard times, they come to everyone, both new and veteran. The key is how you handle them.