Alpha/Beta Parameters of BJT

IMHO it's very useful to know all this stuff, even if you don't use it from day to day, as it deals with the fundamentals of what makes everything else you use IC-wise work.
Whether it will be of "practical use" depends on your field, nowadays especially there is much less discrete design, but if you are designing e.g. a high quality audio amp (I personally work on a lot of all discrete analogue audio gear as well as uCs FPGAs, etc, but I think this probably not so common) or designing analogue ICs, precision test gear, etc then knowing how to work with the above is essential. You generally wouldn't sit down and use all the equations you mention for a design, more recognise the effects of them and know how to compensate (or indeed make use of them)

Knowing the fundamentals gives you grounding you need to make confident design decisions, track down problems and understand why things in practice often look nothing like they do in SPICE.

"The collector current Ic comprises of two components. 1)alpha times the Ie, 2)the reverse saturation current Icbo...."

$$I_C = \alpha I_E + I_{CBO} \tag{a}$$

Now, $$I_E = I_C +I_B\tag{b}$$

then, $$I_E=\alpha I_E + I_{CBO} + I_B\tag{c}$$

I think you used the approximation that \$I_C = \alpha I_E\$ somewhere in your calculation. Remember that \$I_C = \alpha I_E\$ is valid only if \$I_{CBO} = 0\$.