Happy to help. I was intrigued by some of your expressions and thought I'd try and match them. Here are some clarifications:
on the up and up -- can describe a project (situation), person, or company
- company ('Google's really taken off since they figured out how to harness the power of advertising')
- project, social trend ('It was in 2002 that the Atkins Diet really took off')
- project (business deal, investment, idea) ('he was going to start up a website selling shoe laces, but his plans went south when the internet bubble burst in 2001')
- object ('my computer went south last week'--ie it broke)
- company?--it would mean 'go bankrupt', but I'm not sure if it's used.
take a nose dive
- ongoing project (career, relationship, self-confidence, business relationship) ('Their relationship took a nose-dive when she caught him opening her personal mail')
- company (enters a difficult period, but without necessarily going bankrupt) ('Marks and Spencer's took a nose dive when people decided their clothes looked "frumpy"')
- other group, eg sports team ('Manchester United took a nose dive when Rooney injured his leg in a scuffle outside a pub')
- 'it all' [we tend to say 'it all went pear-shaped for X', rather than 'X went pear-shaped', although this is possible too]
- project ('My plan to treat Sue to a fancy meal for her birthday went pear-shaped when I realized I didn't have any cash)
- company ('It all went pear-shaped for Wimpy when McDonald's arrived on the British hamburger scene in the 1970s')
go down the tubes
- project ('If we don't send that check off by Friday our holiday will be down the tubes')
- company ('British Leyland went down the tubes when people realized the cars they produced were crap.')
Ant it's true that 'my life' or 'my world' are usually what the bottom falls out of, but here are some more ideas:
- The bottom fell out of the European textile market when tariffs on Chinese imports were abolished ('market' is particularly common).
- The bottom fell out of his defence when the police found the murder weapon with his fingerprints on it.
- The bottom fell out for Kerry when another Vietnam Veteran took to the national stage and made the case for the War on Iraq. (Sorry if this is too topical--it's taken from the internet.)
mise à jour ok