Proofread a one-page German business letter (Austrian register) + 2 short messages - native speaker

I'm a Croatian systems engineer writing to Geschäftsführer of mid-sized Austrian manufacturing companies (100–300 employees) to ask for a 20-minute research conversation. It is a genuine research request, not a sales letter, and it must read that way. I need a native German speaker with experience in Austrian business correspondence to proofread three short texts (about 450 words total): A one-page letter to a Geschäftsführer (the main piece). A two-sentence LinkedIn connection note. A three-sentence follow-up message. What I need from you: Correct grammar, spelling, and punctuation. Register: the letter should read like it was written by a careful, well-educated non-native who has good German, not by an agency, and not like a translation. Formal, sober, respectful, no marketing tone. Austrian conventions: salutation and address with academic titles (DI / Dipl.-Ing., Mag., Ing.), letter layout for Austria, anything that would read as "German from Germany" to an Austrian reader. Flag, don't rewrite: keep my sentences and their order unless something is wrong or clearly awkward. Where a sentence sounds translated, salesy, or pushy to a native reader, mark it and suggest one alternative. I want to recognise my own letter afterwards. One specific check: the short data-protection notice at the bottom (DSGVO Art. 14 reference) - does it read natural and non-threatening? Deliverable: the three texts with tracked changes (Word or Google Doc), plus a short list of comments (5–10 lines is plenty): what you changed and why, and anything that would make an Austrian Geschäftsführer stop reading. Please include in your proposal one sentence about your experience with Austrian (not only German) business writing, and answer this in one line: what is one thing that reads differently in a letter to a Geschäftsführer in Austria compared with Germany? Confidential: please don't reuse or share the texts.