Do nothing. Stick with the default unless there is a valid reason not to.
I see you mention setting up a new unix developer on a Mac. If this developer has any Mac experience, he'll be used to the default and will probably get confused if you've customized things. If you're writing software that ships out to customers, the customer will (usually) have the default configuration and so trying to debug on a system that is "unfamiliar" (i.e. not your comfy customized environment) can be very frustrating.
If (like me) you work with many different machines and operating systems you quickly learn the defaults for that system, what keyboard shortcuts are portable between systems, standard commands for each OS, etc.
What you really need to do here is get a new machine, see what doesn't work (looks like UTF-8 support is fine, I just checked on my Mac) and see if there are any valid reasons for making changes. Developers have their own preferences when it comes to the command line and really don't appreciate being forced into using what someone else thinks is an "ideal setup". It might be ideal for you, but Apple are pretty damn good at figuring out sensible defaults.
The only thing I'd really change by default when setting up a new Mac, is making the Tab key cycle through all controls (including buttons) rather than just text boxes and lists. I know it's not terminal-related, but it does make a huge difference for us keyboard junkies who rarely lift their hand to use a mouse :)
Keyboard & Mouse > Keyboard Shortcuts > Full keyboard access > All Controls
I altered my command file to resemble the following:
#! /bin/bash
echo 'connecting...'
/etc/netlock/cvc -c connection:account:password
read -p "Press a key to disconnect."
echo 'disconnecting...'
/etc/netlock/cvc -d
Best Answer
One option is to use System Events to send the keystroke necessary to create the new tab, but the limitation is that Assistive Devices in Universal Access must be turned on and adding a sight delay may be necessary.
As far as I can discern from the Terminal script dictionary - you can only retrieve information from tabs but not create new ones as you could with windows (eg. Run do script "clear"