No. Personally I drag the app to the dock so it's there permanently. And if the app's open it's automatically in the dock anyway (like all open apps.) It sounds like your system is a little unstable. For OSX LW has had a problem with ram & VM overuse. The newest versions such as LW 4.2.4 have overcome this partially. At least the ram usage settles & vm tends to also but can still use over 1 GB if you have a lot of incomplete files & shared files. Reduction of LW's ram use can be achieved by deleting obsolete search results (yes they stale go after some time), only having the search window open (ie: LW's menu View>Show/Hide & hide all other windows), & hiding LW (CMD or apple key & H for 'hide'.)

May I recommend you do these things: Safe start & Repair Permissions & also use disk utility & other apps to do repairs & possibly defragment your HDD (though this is less important in OSX.)