Call the phone number on 罚单 for the options

There should be a phone number on your citation(罚单).

1． 我看到罚单上有写“points will be assessed as applicable” 这是不是先生的驾照的point呢？就是说交了钱还要扣点？
Most likely.

2如果是，这会不会影响我们以后车保险涨价？他当时开的是租来的车付带保险。
Probably. Since it's the only moving violation your hubby has, the impact on your auto insurance is probably very minor if all.

3是不是可以选择上课来免扣点。如果是，还要交罚单吗？
It's possible to take defensive/safty driving class so no point will be taken and the violation is not going to your hubby's record, meaning your auto insurance company won't even know such citation exists. But you have to call the phone number to know if you have such option. Changes are you can do that. The fine is not necessarily reduced as it's revenue to the city/county where the police pulled your hubby over.