Adding ingreedients as a percentage

It would be great if I could just specify the percentage of the ingredients and have it calculate my amounts to hit a specified gravity given my equipment profile.  You can fiddle and do this now, but it would seem trivial to sort of automate it.

Also, Can you allow the entry of ingredients as pounds and ounces rather than just pounds?

You can enter ingredients into the recipe in whatever unit you wish.  If your basis is pounds, you can enter 'x lbs yy z' and the program will convert it all into pounds.  I often enter recipes which are in pounds as 'XX lbs' and let the program convert it into kg.

In terms of percentages, you can enter in all the grains (for example) and then click on 'grain pct' on the right hand tool column and adjust the percentages as you wish them to appear. 

In terms of adjusting the grain bill or hop bill to your desired gravity, you can click on the slider for 'Est Original Gravity' just below the ingredient box and enter in your desired target OG.  The grains will be scaled to achieve that target given your stated efficiency. 

The same can be doing with hops, both adding them and them adjusting by desired IBU contribution and using the slider for 'Bitterness (IBU)' to adjust the total to your target.

Wow...  I need to find the instruction manual to find out what else I'm missing.

You can start by looking at Brad's blogs specifically about the software.  There are also a number of threads here on the forum that you can search through using specific key words related to what you want to know.