We fell upon the same pattern: 2 different parks w/ a break in between also. I suggest you make seperate touring plans for each park within each day: look
at the wait times and focus your FPPs in whichever park will save you the most time. Use titles like ‘Date Park am’ to help you easily sort through them in Lines later.
Look at the crowd cal to help you figure out which parks you will go to on which days. Assuming Rivers of Light is happening when you arrive, you will need a minimum of 4 nights: one for each park/show. I also like to rope drop each park at least once.
Keep EMH in mind as a great perk. EMH am is always ideal and pm works for shows, generally just extending the day, attractions that rarely have waits, and e-tickets in the last hour or so.
Keep in mind that it may behoove you to only choose one or two (instead of two or three) FPP’s in the early morning as it may give you a better, earlier shot at other FPP’s. See the (dated) graphic here: http://blog.touringplans.com/2015/05/06/fastpass-plus-availability/
The above may be especially effective in a tiered park where you’d want to get more of the top tier but are only initially allowed one choice in that tier (eg Soarin vs Frozen in Epcot, or Toy vs Rockin in HS).
Always, always arrive 45min-1hr before opening and focus the first hour or so on attractions with the longest waits that you could not get an FPP for…this is especially key if you are hoping to a park in the afternoon that has your preselected FPP’s. For example, if I rope drop the DAK, I can get most everything done quickly without FPP…so those preselected FPPs would generally go to the afternoon park.
It would often be the case that the park that you hop to would get your preselected FPPs but not always: if you start at EP and want Frozen AND Soarin, you’d be forced to FPP one and rope drop the other as I’d guess that day of fast passes for these- especially Frozen- could be impossible/hard. I don’t think it’s possible to do both of these with minimal wait without rope drop. (Note the link above is not that new…I wish @len and gang would update it as it is very useful and- especially now w/ the changes- very relevant; but, all you really need to know is obvious: the most popular attractions sell out of FPP as early as noon). In this case and after I have my Soarin or Frozen FPP, I’d look at my morning and afternoon plans for long waits while considering which of them could still be available day of…prioritizing the FPP’s that will ‘sell out’ first.
If you want to get into the weeds even more,check this out: http://blog.touringplans.com/2016/05/04/walt-disney-world-fastpass-strategy-update/
PS. I hope DLR doesn’t go this route.