You misunderstand what the debt ceiling is. The debt is already incurred, meaning we are already obligated to pay for that existing debt. Raising the debt ceiling allows congress to borrow as needed for short term income to pay off incoming debt. It does not authorize additional spending or incurring any new deb (only congress can do that with spending bills). I assume by 'doom', you are generalizing. We've already seen one immediate affect of not raising the debt ceiling the last time they failed to do so. Our credit rating was dropped, costing us billions more in interest, much like your interest rate spikes if you miss a payment. This isn't rocket science. Our credit worthiness allows us to do things that a poor credit rating does not. It's really just that simple.
The root cause of 'spending' is Congress, not the debt ceiling. The right has turned the debt ceiling into some bogeyman without any context as to what it is, and why it's necessary to raise it.
If you are looking to address a spending problem (ex: live within our means), then tell congress to stop authorizing such spending. They control the purse strings. Playing with the debt ceiling is like giving your children your credit card, letting them max it out, and then refusing to pay the bill when it shows up in the mail because you think it was irresponsible to let you children max out your card.
Regarding your 'mentally ill' statement, a mentally ill person could certainly harm someone with a knife for example. but it's unlikely they could commit mass murder without being stopped. They could do the same with a rock, but again it's unlikely they could kill 20, 30, or more people before being disarmed and contained. I suspect you knew that before you put up that particular straw man argument.
For you climate change question, you are making an assumption that the short term result is harmful, when in actuality, one may see an increase in growing seasons. That doesn't mean it's not harmful, but rather shortsighted to assume that those changes will remain beneficial. Eventually when the increase begins to affect planetary ecosystems to such a degree that they break, you are faced with flooding, increased storm activity, etc.
As to short term damage, you need only look at the last few decades of increased storm activity, both in number, and in power.
Here in the US, we also had two record storms that caused billions in damage. Each considered a 'storm of the century' except they both happened in the same decade (Katrina and Sandy). As the temperature increases, climatologists predict even more increase in storm severity. You are providing yet another straw man argument that says "Look here..short term, this hasn't caused any issues at all". The same could be said for poison, until it reaches a toxic level.
That two week 'vacation' as you call it had a larger impact than simply sending people home for two weeks. Those two weeks without pay affected every business that takes such money in, affecting their bottom lines, which in turn affects the goods that they order and produce. The work that would have been done in those two weeks became backlogged, causing new work when they return to also be delayed. Any fees and fines that would have been collected by the government were lost revenue. Any contacts that the government would have spent would be pended or cancelled, causing more ripples in the business sector. The CBO estimates that the shutdown costs about $300 million a day in lost economic activity. The shutdown was never just about 800,000 people being sent home for two weeks.