First let me state, I am a former vegetarian so cooking big things of meat makes me nervous

as my formative cooking years didn't involve meat. That being said, I would love some advice about a dinner I am putting together next weekend for 8-10 friends. We are having a girl's retreat together and each of us is taking on a meal. I need something not too time intensive.
I will be focusing on whole pork tenderloin for the main dish. The pork will likely be simply seasoned and roasted. My inclination is to season with salt, pepper, garlic, and rosemary and throw in vegetables to roast along with the meat. I have however seen a few recipes for tenderloin with apples and onions in the pan.
Q1- Any thoughts on which version might make a better mid-winter meal?
Q2- Should I pan sear the meat first or can I just put it in the oven?
I was thinking of starting with a nice salad of mixed greens, toasted filberts, dried cherries, and some flavorful hard cheese. I want to make the dressing myself as storebought seems to often overpower the salad.
Q3- Does anyone have a good recipe for a raspberry vinagrette? or would these flavors be better off with another type of dressing.
Q4- Is this meal rounded out sufficiently or should I be thinking of additional sides? If yes, any suggestions.
Q5- What types of wine would be best with this kind of menu? I am sooo clueless about this area.
I appreciate any help you may be able to offer. -B