1) It seems my newish and expensive DrayTek (~350USD) router and my MBP don't like each other. No matter what settings I play with it drops, and has a fairly weak signal compared to what the PCs get. But it seems that on all the cheap routers I could find, there was no problem. That sucks a bit. Not sure which end is at fault.
You could try calling the company or e-mailing them, or going to their site/Googling the issue if you haven't already. You say that using G works for now, that's good. It should. I had a weird issue though with my old one. Deleted it in System Prefs, then also deleted in it in my Keychain, then ran Onyx to clear the caches and restarted. You can even try to reinstall the latest OS update if you can. Then re-add it. That might not help you either if you've already done so, but I'm wondering why you didn't just buy one that had N capabilities if you paid that much. Might need to still play with it if you still have issues.
My USR sucked with my Mac, but I had problems with it on my PC too. I got a refurb Apple, and it's pretty good. For an N, it wasn't that expensive either.
2) Reinstall of OS fixed eject issue. Shame I had to reinstall Leopard on a virgin machine to get Leopard to eject blank media. It would not even show desktop icon for inserted blank media before the reinstall.
I always re-install from scratch on a new machine. I hate the default. Give you the option to deselect some things you may not need too.
3) Trying ForkLift right now but it's not as good as Directory Opus on PC. There must be more dual-pane file manager things out there?
The only one I know of is PathFinder, but I didn't like it. I use others to enhance Finder, like Default Folder X, but it may not help you with this particular thing you want to do. Try searching Version Tracker or MacUpdate to see if they have something.
4) Nothing I can do about it, so if it is a very short business trip and I only need the Web browser, I just take my titanium Sony Vaio.
I have to ask what kind of Sony you have. In my experience, accept for the ultraportables, Sonys are usually bigger than the same sized Mac equivalent. The 15" is going to be bigger than a 14 or 13", but it's one of the smallest, lightest, 15" I know of.
Keep posting if you have issues. Apple and Macs aren't perfect, don't let anyone tell you they are. They're just nice. As you've seen. When they work.