That's a lot of fat in your diet- but as long as it isn't making you too full then I guess it's ok.
The reason you have all that lower body strength is that you're doing lower body every day (which is fine) but not balancing it out with the upper body work. The back and lats tend to respond to volume much better than strength, so 5 sets of pullups would be better than weighted ones (or chins, just because chins are easier. You could switch them up.) As far as training to failure, see:
http://www.youtube.com/watch?v=WPH-irhsum8
One possibility for you losing strength when you only peak once a week if that you haven't reached the end of your noob strength gains and thus you're still better off doing 3 full body workouts a week (actually you said it yourself that deadlifts and squats you are still a newbie to). Once you can back-squat 1RM 275 or so, deadlift 325+, and bench 225 for 4-5 reps, then you are no longer a beginner (regardless of how long you've been training) and you would benefit from doing 4 day splits such as 5/3/1 or something. Until then, 3 day full-body workouts are better because your protein synthesis will stop between 24-48 hours after training without chemical enhancement. In other words, your muscles are ready to be trained again and grow more. If you find that it's too much fatigue, it's likely that your body is just not used to the work yet and you just need to get enough food and sleep for a couple of weeks. When I first switched to 4-a-weeks (5/3/1 BBB challenge) I was dying and thought I was overtraining. I kept eating, dialed back the intensity a little bit for a couple of weeks and now I can't imagine working out less than 4 days a week.
I'm curious why you chose to do dips but not bench press, and db presses but barbell press? Those (along with pull-ups and pendlay rows) are the upper-body mass/strength builders. You are also using an overall very low-rep programme. It's generally recognized that training in all rep-ranges a good way to produce both muscle size and strength. Ex. 3x5 work for the main movement followed by assistance exercises for that group done at 5x10 or something. Do you really feel that you've worked hard enough on a day like Saturday where you do 1x5 and then two assistance exercises?
As far as not gaining too much fat on your way to 180- that's simply a matter of diet. If you can't put on that much muscle each week/month, then don't eat that many excess calories. If you eat enough to gain 4 lbs a month, but your body can only gain 1 lb of muscle/month at your current level then 3 lbs of that will be fat. If you lower your caloric excess a bit (what is called a "clean bulk") then your weight gain will be less fat and more muscle.
This is a good routine for beginners (again, see my definition of beginner):
http://forum.bodybuilding.com/showthrea ... 063&page=1
Based on 5x5 but with added assistance exercises to supplement upper body growth.
