I am not commenting on your whole translation here, just the parts relating to 与.
As for the first passage, in the first case 与 is used to show that the link/connection is between the two items connected by 与 (literally it would read like: the A and B connection, i.e. the connection involving both A and B, which we say as between A and B). As for the second case, we can analyze it as follows: [公关公司职员]通过[[与媒体编辑或记者]的联系和沟通]，[将[客户的需求]]软性地传递给[目标客户群] -> [the PR company's staff] through [[with media editors or reporters]'s relations and connections], [OBJ: [client's demands] gently convey to the target demographic] -> Through connecting with the media, the the PR company's staff gently conveys the client's demands to the target client base[?] (perhaps target demographic? I'm not 100% sure with business jargon).
在与客户的接洽方面 can be dissected as 在[与客户的接洽]方面 -> regarding/on/concerning discussions with customers. As with the first passage, 与 is bringing together two items that are connected (in this case the two parties involved in the talks), only in this case the first item is omitted. The next 与 is the same as described for the first passage (the interface between ... and ...)
as for 具象品质, the definition I found for 具象 has it as the opposite of 抽象, so perhaps: practical/effective product quality