Based upon stretch from day 21 to day 23 in your diary, it stretched quite a bit. Get the light closer or increase intensity an other way. Do so incrementally and slowly.. wait for plant to show you what the change caused. Get that internodal distance a little shorter. the stem might turn pale and weak shortly, otherwise.
as far as other stuff... plant looks healthy.. status quo, otherwise? as long as that new growth green fills in quickly, it's likely nothing.