There are some caveats:
Maxrequests actually maxes out at 8. No point in setting it higher.
Some servers don't implement HTTP 1.1 completely. Rather than dealing with this, most browsers default to having pipelining turned off. If the sites you visit regularly end up timing out, you may have to switch pipelining off.
It may not be a good idea to change the default for the screen paint delay, particularly if you don't have a really fast machine. A perky machine can deal with incomplete information pretty well, but a slow machine will be slower without the initial delay.