Yes these are rated for outdoor use.
The lights are approximately 10 inches apart. The bulbs are C7 bulbs and they are replaceable.
Yes you can connect together with other sets. Please make sure to review instructions on how many sets can be connected together.
Full length is approx 44 inches.
why not? they are in the business of selling. you snooze you loose.
Yes, the bulbs can be replaced.