Let's discuss those questions.
How did Musharraf end up making so much money when he was in fact a government subordinate and retired with not much (relatively) money? The answer to that would be that since his self imposed exile, Musharraf has gone on various international lecture series and tours. The average compensation for one lecture is $100,000 (that's almost 1 crore rupees, give or take). Now in the past 4 years if Musharraf has even done 25 lectures, that means he's earned 25 crores. Assuming he is an educated man and is not overly stupid, he must have (and he did indeed) made a lot of investments which have returned handsome profits to him. So where he got his money should be clear for all to see.
Now the second question, why didn't he pay any taxes? Well according to the Pakistan tax rules, residents of Pakistan earning income abroad are not liable to pay taxes on that income within Pakistan. The Pakistani tax rules assume that because Pakistanis send valuable foreign exchange to Pakistan, it is more than enough to not double charge them (unlike the United States of America, where foreign income is tax deductible). Hence, Musharraf did not pay any income taxes for the last three years he was not in Pakistan. The pension he gets already is tax deducted (income tax is deducted at source) and while we do not know why he did not pay any property taxes (maybe the properties are not in his name? Maybe he did pay the taxes through a proxy that don't appear in his name? Maybe he is indeed, a tax defaulter?) we can be reasonably sure that the money he did make is indeed legitimate.
And finally there's the biggest question of them all, one that doesn't even concern Musharraf. What about the other so called "sadiq" and "ameen" (pious and pure) politicians of Pakistan? The one's who are known to be inherently corrupt? For example Nawaz Sharif says he owns only 1.5 crore rupees in assets (maybe he forgot the 600 crore Raiwind estate he lives in is not his own?) while Zardari says he only owns 1.8 crore rupees (of course he also forgot he owns palaces in France, Dubai and God knows where else). And then there's the cherry on top of the cake, Hamza Shahbaz Sharif who says that he doesn't even own a Suzuki Mehran.
Let's take a moment to reflect on this. These gentlemen who claim that they have next to nothing travel in cars that cost around 6 - 7 crore each. They live in palaces that cost hundreds of crores. And they live a lifestyle that is simply not possible on the meager "incomes" that they declare. So my question is this, do you finger pointers not think before you open your mouths to make allegations?