A worker measured 30 MB when fresh and 97 MB forty hours later, on an idle server. Nothing was leaking — that is simply how PHP returns memory.
If every mistyped URL returns your home page with a 200, search engines will index all of them as real pages — and split your ranking across the duplicates.
A static sitemap.xml wins over any dynamic route, and a generator that walks the filesystem cannot see content stored in a database.
Page views, top pages and per-site traffic, from the file already on your disk — no JavaScript, no third party, no Elasticsearch.
No roundups, no “5 tools you must try.” Just the posts, when there is something worth sending.