Hi everyone! i'm a first timer and trying to utilize the reward I got from Chase (107k). I did some reading on the best ways to use UR, but I am still very confused , and nervous that I may make mistakes without asking the expert here. The trip is for me and my husband, from LAX to NRT this November, hopefully get a free stopover in Seoul (ICHN) or Hongkong. It seems like SQ/ Krisflyer will be my best option, but I will need to buy some points since I'll be short ~ 5000 points. So my out of pocket for 2 round trips will be around $500. My questions are:
1) is there a better way to utilize my points so I can reduce my out of pocket cost?
2) can I add any free reward stopover I want (like Seoul or Hongkong)? sorry, these stopovers are not common. During my search, I only see people with stopover in singapore, etc? does it matter if I add the stop over at the beginning part of the trip or the end?
3) if I can'd add a free stopover in Seoul or Hongkong, should I book one way tickets instead? LAX - NRT, NRT-ICHN, ICHN - LAX?
Thank you in advance.

It depends entirely on the award program you use to book the tickets, they are all different.

I would suggest you look at the programs you can convert to from Chase, read up on the airlines you can redeem for from those programs and the miles required, as well as whether they allow stopovers.

If you have reasonably fixed dates you may want to start with looking for award availability first, as its no good converting to the 'best' program if there are no award seats when you want to travel.

You didn't say if your got the 100K from Chase CSR or other cards. If you got it from CSR, you could also look into using the UR points to buy tickets thru the UR portal. A quick check shows plenty of under $800 roundtrip tickets from LAX to NRT in November. If your have CSR, your 100K UR point is $1500. It could cost you less than transferring to airline + buy miles + fuel surcharge.

you can transfer to korean air and they will allow free stopover in seoul. not sure what economy prices are but its 65k one way business or 80k first

I plugged in some estimate dates and found the following using the chase portal (assuming your have CSR)

Dates I used: LAX (11/10), NRT to HKG (11/20), HKG to LAX (11/24).

ANA: LAX - NRT, NRT - HKG, HKG - LAX (3 hour layover back to NRT) 57k per person

AA: LAX - NRT, NRT - HKG, HKG - LAX ALL ONE WAY FLIGHT 66k per person

If you can get another Chase UR cc, you'll be able to cover the flights for 2 at ease.

You definitely have options and if you are using points you can always transfer out to different airline. But the rates from Chase is not bad.

I am not an expert but been through your situation. Feel free to PM if you need assistance.

GOOD LUCK!