i try to do 3 high intensity days, 3 low intensity days and one day completely off. i do tempo on low intensity days but not every time, sometimes ill do a recovery circuit or something else with a similar affect as tempo
just make your own sled, thats what i did. i just used stuff i already had. i used a bag (dont use something you care about it started ripping after two or three sessions), duck tape, string, weights and a belt. its not pretty but it works
EFE is when you do a run typically its split up into 3 20m sections and you do a sub max build up for 20m then you start running pretty hard and then you coast, hence the name you go easy fast then easy.
dont worry i dont mind the questions, i always like discussing training.