STARTER V5.4 cannot be operated simultaneously with other Siemens engineering tools on the same PG/PC, such as SIMOTION SCOUT, SIMATIC S7-Technology, SIMATIC NCM PC, or STEP 7 Micro/WIN 32 (PC version).
On the search results page, look for the entry titled "SINAMICS STARTER" and click it to open the download page. This page contains the latest version of STARTER, which is now V5.7 at the time of writing. However, Siemens typically makes older versions, including V5.4, available as well. Sinamics Starter V5.4 Download
Yes, but only version SINAMICS MICROMASTER STARTER V5.4 HF2 specifically supports MM4 drives. Any version more recent than V5.4 HF2 is designed exclusively for SINAMICS drives and will not communicate with MM4 devices. STARTER V5