ok cool, im gonna make adjustments and explain the reasoning as well:
Day 1 - Chest + triceps:
1stly, look how much chest you do, vs how much biceps. biceps is a pathetically small muscle compared to your pecs, and so they need far less work to reach failure. also, triceps are always engaged in chest excercises, so we'll kill them off at the end of chest. I find that machine chest presses are almost never any good (unless youre JUST starting), unless its like, a cable press or hammer strength one.
-BB bench press x4
-Db flat bench (so you can drop the weight and it doesnt really matter if you fail, you can just drop them)x3
-DB incline pressx3
-dips x 3 (dips are great for shaping, and warm up tris!)
-cable triceps extensionx3
-overhead Db ext x 3
skull crushers are a very very bad excercise for triceps development, the force runs perpendicular to gravity for the entire 2nd half of the motion, so they only work the inital half of the triceps and only do anything if you go really deep.
Day 2 - Shoulder/traps/abs
shoulders are a small muscle, but have 3 heads which have distinct functions. as such, they often take a while to train, but you dont feel physically exhausted, so thats why ive put traps/abs.
DB side raises x 4 (great medial isolation)
DB military press (now do your compound excercise, after youve pre-exhausted your muscle) x 3
front raises x 3
rear raises (on a pec deck, if you have one) x3
DB shrugs x4
as much abs as you want

Day 3 rest
Day 4 - Legs
Squats x 3
Lunges x3 (at least 40 reps, so go low weight, 5/6 kgs per hand)
tried deadlifts - i didn't feel it :/ have to work that out
leg extension with machine superset with leg curls
calf raises
if you find this easy, do lunges first, do your squats on a smith machine SUPER slowly, and put in leg presses before your extensions/curls
Day - 5 Back (2nd largest muscle in your body, so train it alone, or with biceps!)
looking at the order of your workout, and the amount of back work you had, it shows your priorities. abs will come if you do everything else, theyre not something that need to be trained anywhere near as hard as everything else

lat pulldown x4
seated row x 4
DB pulloversx3
DB biceps curl x3
BB biceps curl x2