Can sars-cov-2 cause only dyspnoea/chest and throat tightness? (no fever, no cough)

Very unlikely: Almost impossible. Cough and fever almost always are present; shortness of breath usually doesn't begin until a few days after onset of cough.

Suspicion for COVID: 19 is higher if you have at least 2 of these sx's: fever of at least 99.6, Cough, Shortness of breath, Chills, Shivering, Muscle pain, Headache, Sore throat or new loss of taste or smell. WHO says 88 % of infected people had a fever & 67.7 % had a cough. Many are asymptomatic. REF: www.vox.com/2020/3/3/21161724/coronavirus-symptoms-covid-19-sars-cough-fever. Some stats differ from this.