Those ions are, along with sulfate, called the 'stylistic ions' because they influence the stylistic aspects of the beer as opposed to the more technical aspect of needing to get the mash pH in the correct range. Thus there is no simple answer (though many have proposed simple answers involving things like the ratio of chloride to sulfate). Chloride generally does nice things to beer like soften and smooth the palate, enhance mouthfeel/body, give an impression of sweetness. Sulfate tends to have a drying effect and renders the perception of hops as sharp and coarse. This works with some hops varieties for some people but does not work for all hops varieties nor for all people. That's why I recommend starting out with a low level of sulfate and incrementally increasing the sulfate on subsequent brewings of the same beer until a desirable sulfate level is found. For you personally it may be 0 mg/L or it may be 350 or even more. The sulfate level does not, AFAIK, translate to IBU. Some quite bitter beers (i.e. high IBU) such as traditional Bohemian Pilsners are brewed with very low sulfate levels. If sulfate level in those beers creeps over as little as 20 mg/L the effects of the high bitterness become unpleasant and the beer is ruined. OTOH many of the English ales are brewed with the very high sulfate levels which you mentioned. It seems to be the hops cultivar that makes the difference. And at the same time you can make a better IPA than the traditional IPA by keeping the sulfate level much lower. "Better", of course, needs to have an optimality criterion attached and there is, of course, lots of debate over whether the low sulfate IPAs are really better.
Sodium is at best considered a "don't care' except in cases where there is enough of it that it can be tasted. In some of these cases (e.g. Gose) a salty taste is an important aspect of the style. In other cases the saltiness is considered a flavor negative. High sodium would, in general, be considered a negative.
