I just got my Gibson Les Paul back from the shop where i had a professional setup done. Now im wondering, if i downtuned from E Standard to D standard, will it knock the intonation out of tune? Im afraid to downtune because i tried to set the intonation myself and the shop said i did it wrong, even though i followed directions i found on a reputable website. Also in the same vein of questioning, when i change the strings i change them all at once as opposed to one at a time (ie cut the E, restring E, cut the B, restring the B, etc..) Will this cause my intonation to go out of whack? will i have to re-intonate after i restring? Thanks.
If you change the tuning significantly like you are doing, it is recommended. If you change string guages, it will be to be corrected.
now when i tuned back up from D to E would the intonation be alright? im only gonna tune down to D to learn a couple songs.
If it is only temporary, you should manage. However, if you do anything serious with it, it would be best to adjust the intonation if necessary.