It seems like you’re asking a couple of different questions here Matt, so its hard to give a you a perfectly straight answer without finding out more of what you’d like to do. There are a variety of tools and hardware you can use, but not all may be necessary depending on what your focus is.
Lightworks is fine as a video editor, but I would encourage you to do as little editing as possible. I’ll get back to that later. Most everyone I know uses Adobe Premiere, but it doesn’t do anything that Lightworks couldn’t accomplish for this task.
One of the best USB microphones I ever bought was the Yeti by Blue. It’s looks a little dumb and it doesn’t mount terribly well, but the quality is incredible for $130 (the nano which has similar guts is only $99). It has multiple microphone patterns that make it rather versatile when needing to record both directional and omnidirectional audio. It’s the best sounding, affordable, plug n’ play mic I know of… everything that competes starts around $300+.
The Logitech C910 is a decent Webcam. The focus can be a little finicky with some shots, but most of the auto features can be disabled via software. I’ve picked up 2 or 3 along the way and have never had a problem with them. There really isn’t much point of getting a 4k camera. The overhead compared to 1080p isn’t really worth it unless detail is paramount (even still it doesn’t make much sense for streaming).
Alright… now lets talk about your workflow. Are you planning on truly “streaming”? Or are you planning on recording everything, editing it, and then uploading it? There are a variety of options between the two, but I would encourage you to adopt as little post-production as possible. The people I know who are the most successful at this spend very little time in post-production. It’s a real time suck (I know, I do it for a living). Focus on minimal edits… throw some branding on the head and tail, done.
You should really take a look at OBS is you haven’t already. It’s free and unbelievably powerful. You can set up multiple cameras (USB, IP, etc), microphones, full screen capture (or individual app windows). It’s a beautiful real-time octopus that can communicate over just about any protocol. You can then setup “Scenes” within OBS to switch between inputs, control transitions etc. It has the option to send the stream directly to Youtube or record it locally for further post.
If you’re interested in digging a little deeper. You might look into a dedicated H264 hardware encoder. It converts a video stream from HDMI to RTSP (Real Time Streaming Protocol). This can be helpful if you’re looking to offload some of the work from your computer to a dedicated device or need something running 24/7. I suggested it to Generator some time back as an option for streaming classes or meet ups (even have a box I offered to let them try out), but it fell on deaf ears.
Feel free to hit me up if you have any more questions.