There are a few options for you.
One is to wear big head gear connected to an mp3-player, then just ignore when spoken to. There is no rule in any gym that demands you engage in conversations with others. This might seem arrogant, and so be it, you want to get strong, not to socialize, so if 80% of the people at the gym think you are an arrogant prick, so what. Smalltak can be done before and after training.
Mixing non powerlifters and bodylifters is always a no-no. Bodylifters train differently and have different goals than the powerlifters. Most people will respect that other people have other goals, but some will not, and you always have the stereotype old boydbuilder who thinks he knows everything there is to know in this world about lifting.
Nothing wrong with trying a heavy single and miss once in a while. Sometimes you need to challenge yourself and see if you can make a lift were the outcome is not certain before you do it. Imo, that' often the most fun part of powerlifting. But there are also other styles, you will also find powerlifters who barely ever miss a lift.
The older you become, the less you will care about other people and what they say. The good thing about becoming big is that you can just stare many noisy people down, and they will shut tight. Or become so strong that they will not give you any advice because they cleary see you know your stuff.
Personally I prefer to avoid any conversation, and just start my next set, even if somebody is talking to me. Or just a quick "Gotta do the next set" and start doing the next set, then they usually walk off. If some people get offended with this, it is their problem, and not yours.
You are strong for your age. This is a lifestyle, not a bragging game, so if you lift 130kg or 200kg in the bench press would matter not, what matters is your attitude.
You will experience a lot of bullshit talk in commercial gyms. Another option is to get your own setup, garage or joing a PL club. Nobody there will bother you when you go heavy.
Personally still squatting heavy (and heavy singles too) after 10 years of squatting, and I know people who have been at it even longer than that.
To me it seems like this old bodybuilder at your gym just tries to show off. He has no fucking business talking to you like that. You could attempt to file a written complaint with the gym if you feel like. Fact is, if you don't want his advice, he has no right or obligation to give it to you, and when he cries the advice out for all the gym to hear, that just shows what kind of an ass he is. To some people the world is not how it really is, but how they are. So he looks at the world from his own viewpoint, and find it to be the only truth. For that very reason he does not seem very smart. An intelligent man will be able to see the world also through the eyes of others (ie. see the case from their viewpoint).
Keep doing your thing. Powerlifting is something great, stick to it.