I'm actually a fan of bow ties, although I rarely wear them. If I were you I'd choose another pocket square though, as it doesn't seem to go with the look. Sometimes contrasting patterns can works but something about it just seems a little off to me. More information on what type of event you're going to would help us give you more suggestions. ;-)
Thankfully he was wrong, it's been over ten years since the OP posted and Walmart didn't become the next Ralph Lauren ha ha. ;-)
In all seriousness, people tend to dress casually these days as society and the average work place tends to be more relaxed. However, there will always be men who care about dressing well.
While I prefer the button down option as it's clean and classic, you might want to consider getting a few shirts in each style as it's always good to have different options available and to change up your look a little on different occasions.
Yeah, to be honest I'd put the money towards a trip too, rather than invest it as I'm not sure there's a legal sure fire way to double or triple your money. You could put it aside to invest once you have a bit more perhaps .. Either way, finding out you had $1500 in your pocket is a great situation!
It's perfectly fine to keep a few pair of casual street shoes, however I'm not really a fan of the pair you posted but we all have our own individual taste and sense of style. Basically if you still like them then keep them if not then perhaps donate them or sell them online. As for when to wear the shoes you posted, they'd be ok to wear while running errands or during the weekend.
Well done on taking on some of the advice we gave you on your first outfit, this outfit is far better than the first! :-) You're a fast learner if you take on some of the advice given to you above you'll be dressing sharp in no time. Don't worry about making the odd mistake, I cringe just thinking back to the outfits I wore 7 years ago.