Metallian said:
1) How did you get the increased crafting speed?
Uhm... at first I mistakingly used sp/day instead of sp/week. Then when we figured out that was wrong, my DM generously allowed me to keep doing it that way, because it fit with the character.

I.e. I got it for free, and it hasn't proved overpowered at all.
Mind you, it still takes hours to days to make something useful. I do a lot of alchemy, and at 40-50 gp per day, I can essentially crank out one or two one-shot items which are much lower power than any of the spells the spellcasters can fire off at the same level...
2) Do you have any suggestions for someone who wants to play this type of character? Is the "techie/equipment guy" pretty much a lost cause in D&D?
(1) Don't do it if you're a powergamer. It's a great creativity/roleplaying opportunity though.
(2) Don't give in to temptation! There's often an easier or cheaper way to do things via magic. You could buy an amulet of water breathing instead of inventing the first breathing apparatus. But see (1): you're doing this to have
fun, not to have the most powerful possible character.
(3) Constantly think "how else could I approach this problem"? You can't just coast along with a character like this. You'll have to stay on your toes and keep thinking of clever stuff to do, or chances are you may not have much to contribute.
(4) Get a Haversack and fill it with pre-crafted gadgets. I have a list of well over 200 alchemical items collected from various published sources, and my PC is currently carrying more than 50 of those around with him. Gotta have something useful for any situation...
(5) Even with faster crafting, you'll need to make the best use of whatever spare time you get. Our own campaign is largely ship-based, which means that I can actually get a lot of crafting done
while we travel! In a land-based campaign you could do something similar with a covered wagon and a hired driver.