Former 717 LAX here, hopefully I can offer some insight.
3 Airports
Best way between the airports is definitely Uber/Lyft though I utilized shared van services a couple of times that saved a bit of money but not necessarily worth it if you are tight on time. Be prepared for some drivers not wanting to make the trip from SNA to LAX, had one guy accept the trip one night then drop my captain and myself off in a parking lot where Uber drivers hang out and told us good luck.
Hotels/Crashpads
Never used a crashpad as my trips were mostly commutable so relied on a mix of hotels/Airbnb when I needed it. Priceline/Hotel Tonight garnered the best results usually just be careful to choose a hotel with airport transport. Only once got a hotel for less than $100 usually a bit higher out the door, there are a few Airbnb options but you need to Uber/Lyft to them.
LAX Traffic
This airport sucks to drive into. I once missed a commute home from SNA (late release) because it took 30 minutes to drive the 3 miles onto airport property during the red eye push. Not much you can do it about it, thought about hoofing it that night but probably would've been ran over. Plan ahead if you can, there is a new project to connect LAX with public transport better but its a ways off...
https://www.lawa.org/connectingLAX
The Commute
Commuting wasn't bad for me, plenty of options but occasionally there'd be 5 guys standing around for a jumpseat so you can be flexible with 3 airports. Decided to hop on a flight to ONT once instead of vying for diminishing opportunities to get to work. Cost me an Uber but made it with no worries. That is one advantage over most commutes having multiple airports in a pinch. LAX has redeyes to a lot of places for backups as well.
Hope that helps, the CPO is nice and has a good sleep room if you need it. Terminal 2 & 3 basically suck because they are so freaking busy even though one is new it's always a hot mess. Sometimes if I commuted in on Spirit or AA I'd walk around the long way through Tom Bradley and chill there for a bit as you could find a quiet spot easily most days with more food options. If you don't have it yet, recommend a credit card that offers lounge access for your sanity too.