You can dose aromasin at 10 mgs EOD without any problems. The 12.5 dosage is given because there are many tabs that come with 25 mgs, and need to be split in two. However, there are also many products dosed straight at 10 mgs, which is also fine. In fact, this is the dosage I use, and don't experience any problems whatsoever.
You are wrong here, since there is a ton of labs and pharma companies, which can, and do produce it in caps. After all, the powder with the active substance is just the same, so it does not really matter if it comes in tablet form, or capsules. If dosed properly, it will not kill the estrogen levels - it is all a matter of dosages.
The dosages of nolvadex and clomid used in the perfect PCT protocol are pretty moderate, so they will not reduce the estrogen levels to such an extent, while they do work great in synergy to stimulate the natural production of testosterone. Meanwhile, it is best to use aromasin (which is tappered down throughout the PCT) in order to prevent any possible estrogen related issues, and any estrogen rebounds. After all, during the PCT your testosterone levels will also drop, so there will be a disbalance between testosterone and estrogen, since the latter one will not drop like testosterone will. Therefore, you need to keep that in mind too.
As for the liver support, the one recommended in the perfect PCT protocol is a very complete supplement, with over 40 ingredients. Therefore, it is extremely beneficial for your health, and it will give a very comprehensive support after a cycle, which is when your body is all stressed out. Besides, many injectable steroids are also liver toxic, so you should not think that oral steroids are the only ones posing a threat to your liver. Finally, all those supps in the perfect PCT are not liver toxic.