If you want to give feedback about LW 5, post over at the LW forums. The developers will see your post there (the helpers here are volunteers - we don't work for LW) There's a section for comments about LW 5. LimeWire Forums

You can search by artist or album in LW 5. Click on the All button > Advanced Search. If you click on Audio, you'll see text fields for Title, Artist, Album, Genre etc. And if you just do a general search, you can refine the results to show only the artist or album that you're interested in. Once the search is underway, type the artist or album into the 'Refine Results' text field... then only those results will show.

If you're seeing spam files in your searches, check out this thread for info about adding words to LW's keyword filter & lots more general info: How to find music