The trim from the top method is what you are referring to on Barefoot for Soundness, correct? I really dont' like that method, as it promotes excess thinning of the wall. I think if someone had a lot of experience trimming a different way first, they could do alright with it, but personally, I don't see as many good results from it.
If you address the flares on the bottom by a good bevel, the top apperance isn't as important, as that will grow down and out, if you are beveling correctly, though it's okay to take SOME of the flare off the top, you don't want to thin the wall in most cases.
The white line doesn't look so stretched as it just has old inflammation, so a good bevel is probably the most you need. In most cases, you don't want to take the wall so short, or thin. The sole is more likely to be bruised and the hoof needs the protective shell the wall provides from the top to keep out infections and just a general protection of the inner structures. Right now, the heel needs to be brought down and balanced with the other side, the left alone for the toe wall to come back in. If you can get some foam pads (see my website if you need help locating some) and until you get your boots, duct tape some pads on, if your horse seems sore.
The quarter crack looks like it's more likely harboring a fungal infection, that won't go away no matter how you trim without some treatment (clean trax, white lightening or ACV soaks).
WIsh I were close to you, I can help you get the right boots to fit, and most of EasyCare boots come separatly, so you can order the individual sizes you need.