Newtonian Mechanics and Forces Problem

Problem, Work, and Solution: [Broken] (You can zoom in if needed)

Sorry for not using the template, this was done in MS Paint and I didn't want to have to type it all out again... Basically, the problem is to find all tensions (ropes/strings are massless) and the acceleration of the system, all in terms of given masses and frictions. The large rectangles are stationary and the circles are massless, frictionless pulleys.

I'd really appreciate if someone could check over this, I did myself more than once and also with numbers, assuming m1 = 1kg, m2 = 2kg, etc and μ = 0.5, it came out to be...
a = 2.613 m/s^2
T1 = 12.413 N
T2 = 27.438 N
T3 = 5.878 N
T4 = 35.93 N
...which seems right because m3 will actually lessen the tension on T3 but T4 will still have to pull all 5 masses so it's higher. Based on the reasonable masses I used and pretty average friction value, I think my answers are right but I still want to be sure.

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Anyone? This is due Monday...
Equation for acceleration looks right to me.

For T1 however it should be this in my opinion

m1 a = t1 - m1 g

EDIT: Oh, it's the same as yours. Sorry!
T2 also is fine and so should be the rest.
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