questions on deprecated section of base

Again, I'm a noob, so your patience for my ignorance is appreciated in advance.

1. Wouldn't setting deprecated elements to say, big and red help the designer more than just neutralizing them?

2. I'm not sure why the following rules are included in this section, as opposed to the reset or general sections. Please let me know to what extent any of these are actually deprecated?

.content table[border],table[border] {
border-collapse:separate;
border-spacing:0;
}

body {
background-color:transparent;
}

img {
border:none;
margin:0;
}

ol {
list-style-type:decimal;
}

td,th,tr {
background-color:transparent;
border:none;
height:auto;
vertical-align:inherit;
width:auto;
}

I have to say Tripoli's a great learning tool, working my way through comparing this and the Firefox defaults, Eric M's reset etc is a great exploration. . .