Nice start to the journal...
About toning the triceps - while hitting them hard with a good exercise programme will tone them, sadly (since spot reduction's a myth) the only way to expose that toned muscle is to reduce overall bodyfat. A balanced programme, covering all the muscle groups, will do that.
Your programme looks like it covers the basics (neat SM squats with 50kg, that's awesome) - but a lot will depend on your diet, and also how much cardio you do. Incidentally, cardio works best after weights - although if your day 3 is just cardio-then-abs, it's probably not going to hurt.
If you were looking for suggestions on a good four-day split (leaving Weds for cardio), a four-day split for someone with your eight-and-half years of previous experience might go like this:
A. Chest-triceps (so, three chest, such as a barbell bench press, a fly and maybe pec dec or an incline press, and three triceps from your list)
B. Back-biceps (lat pull-downs or chin-ups, deadlifts, and a row (bent-over, db, or t-bar), then essentially three curl variations, like EZ curl, preacher machine curl, seated hammer curl, etc)
C. Legs (quads, hams, calves - so Leg extension to warm up, squats, presses or lunges, then lying or seated curls, stiffleg deadlifts, and standing or seated calf raise)
D. Shoulders-Abs (shoulder press or clean-and-press, side raises, rear delt work, shrugs, and three abs to try to hit obliques and upper-lower abs).
It would probably be better to avoid doing chest and back the same day, which is why it's quite common to split arms across two days. Chest and back are both bigger muscle groups, hence the big-plus-little split. A routine like that would work equally well with anything from 5x5 thru three sets of 12-15 - as long as the intensity's up there - as 1day says, feeling muscle soreness is one pointer to that.This site
has some good suggestions on exercises to add in, often with illustrations.
Just my 2c worth, there'll be more advice from more experienced folks, i'm sure.
There are no reasons, only excuses.