1. Swallowing will slow you down when it comes to getting to SP and eventually a dream. Most of the time your salivary glands slow down to a crawl so your mouth doesn't overflow while you're asleep (a.k.a. drooling) but when you first lay down it is likely that they'll still be active. It's fine to swallow during the first couple minutes but after that you shouldn't really need to.

2. Yes, images forming and appearing before you is normal. When these images start becoming noticeable just try your best to zone out a bit. You know, like day dreaming while staring out a window or something. Just don't put all your focus into it since that will likely wake you up. It's a delicate balance and comes easier with practice but it's not very hard.

3. Think about calm thoughts. Have you ever meditated? If you have then just have the same mindset only with lucid dreaming on your mind. This allows your mind and body to be relaxed and ready for sleep/dreams. If you haven't then it's really just keeping your mind as relaxed as possible. Think soothing thoughts about whatever makes you calm/in a good mood. Personally I enjoy just the peace and quiet and allowing my brain to have nothing on it's mind but it's different for everybody.

4. Just like before it is different for each person but it is usually after 10-20 minutes. Some people have this happen after only a minute while others need to lay there for 30 minutes or more. It also depends on how quickly you fall asleep and how well you can maintain the balance between a full waking state and a lucid-dream state since they are both cognitively similar. If you don't see any results after 45 minutes or so and it's a normal day or something with stuff going on then I would just fall asleep instead of losing that hour or so. If you don't have anything going on the days you try though then I would just persevere. Worst comes to worst you fall asleep and have a chance at a DILD/DEILD.

Hope this helps