The LCA lounges are operated by third parties, access is only provided for those travelling on BA, QR or RJ as per the oneworld site:
http://www.oneworld.com/ffp/lounge-access
There are plenty of threads on BA baggage delays and poor communication.
Personally, I have found AB/HG very good for intra-Europe flights. Although a bit of a hassle sometimes, you can get free XL seat selection and often seat blocking.