You have a bunch of things to consider here: neutering, lead work, engagement and exercise, and recall.
The best study on neutering I know of is Hart etc al 2020, which looked at the physical impact of neutering. They found that any time after 6 months was okay for a male lab. My caution would be to think about the dog's mental maturity as well, and leave him till he's calmed down a bit and grown up - but that is just opinion, based on experience with 2 bitches of a notoriously late maturing breed (I wouldn't neuter before 4 unless I had to for health reasons - but as I say, that's me and my dogs and not a large sample and a proper study).
Lead work. If he is dragging you about, of course you want to let him off, and of course you don't want to take him if you're just popping up to the post box or whatever. I'd suggest watching a few videos by Will Atherton - lots on YouTube. My two were decent on lead, but following his advice really improved things.
Engagement and exercise. He needs to focus on you and he needs to find walks satisfying. Try breaking up walks with spells of heelwork (on-lead and off-lead), basic obedience (eg build up a sit stay, gradually increasing distance, duration and distractions - a lot of dogs seem to find a sit-stay hard mental exercise, esp if you're expecting it for 5 minutes and you're at a distance. Do fun things with him too; he's a lab so retrieving should be fun. Does he like food? Every now and again don't just give him one treat for being good, give him 6 or 8, one at a time, so at the back of his mind he's always hoping for that thrilling hit. As for how much, I have a high energy breed. They get about 80-90 mins most days, almost all off lead (because I can trust them), almost always involving some focused training (10-40 minutes depending), and at the very least including random recalls, stops, maybe some off-lead heel, and me changing direction in the woods without telling them: it's their job to keep an eye on me. Some days they have to make do with an hour. Some days they get several hours. But that 80-90 minutes is their basic.
Recall: engagement and interesting exercise should help with recall. Also just repeat repeat repeat. Call him when there is nothing to recall him, give him a reward (a treat, a big fuss, a game), sometimes put him on the lead, sometimes don't. Put him in a sit stay, walk a little way away, recall. Wait till he's mooching at a distance, get out a squeaky ball and brandish it and when he comes running, throw it for him. As PP have said, if he's being a bugger, have him on a longline.
I know dogs like your dog and while I don't dislike them, they do piss me off at times. My older dog shares my opinion here and threatens to punch their lights out when they come barrelling up to her and get right in her face. They're lucky that she's not aggressive, just barks and chases for a couple of strides and acknowledges their grovelling apologies. One day they might not be so lucky.