15 Amp 7-Day Outdoor Digital Plug-In Timer - Black

No, I don't believe so. There's nothing in the documentation that shows that and it comes with them working together.

This timer can ONLY be mounted on a wall. If it is not mounted completely vertical, the safety shutoff kicks in, and there will be no power to the outlets.

Yes, that should work. It has 7 timer programs each with an on and off function. You need 6 for every 4 hours so that should work.

Although I don't have this particular timer so don't know for certain, I believe it is possible, here's why. I have other timers that are similarly designed, with similar instructions. I've provided this same answer to other asked questions of the same nature. From the Installation Guide: 3. Press + or - to scroll to the days of the week that the event will run. NOTE: To set the event to run every: - Week: Select MO, TU, WE, TH, FR, SA, SU - Weekday: Select MO, TU, WE, TH, FR - Weekend: Select SA, SU Note the wording in the sentence at "3: Press + or - to scroll to the days of the week that the event will run." This certainly suggests that certain, individual days, separate from others, can be, or must be selected, by scrolling to the day, or the days. For example, you might want the timed event(s) function to occur ("run") only on one day, Wednesday. So you would scroll until perhaps only WE is in the screen, or WE is lighted up in the screen. How you confirm that selection I don't know, since I don't have this particular timer. :) Another aspect that backs up my theory is that for the entire "pre-packaged" *Week* function, it appears that you still have to "Select MO, TU, WE, TH, FR, SA, SU". In other words, even though you want the timed event(s) to occur ("run") every single day of the week, you STILL have to select EVERY single day of the week for this function to be programmed. And the same goes for the *Weekday* and the *Weekend* functions, because the listed quantity of day name abbreviations are less for each of those two functions, five and two, respectively. Again, this certainly suggests that while in this area of programming, selecting the actual, individual abbreviated day names is necessary to program any of those three functions -- Week, Weekday, or Weekend. So, technically, a fourth function is just for one day only, per the language starting at #3. If they had just written it this way...scroll to the day(s)...it would have been a lot easier for users to recognize and understand the possible variables. The Although I don't have this particular timer so don't know for certain, I believe it is possible, here's why. I have other timers that are similarly designed, with similar instructions. From the Installation Guide: 3. Press + or - to scroll to the days of the week that the event will run. NOTE: To set the event to run every: - Week: Select MO, TU, WE, TH, FR, SA, SU - Weekday: Select MO, TU, WE, TH, FR - Weekend: Select SA, SU Note the wording in the sentence at 3: "Press + or - to scroll to the days of the week that the event will run." This certainly suggests that certain, individual days, separate from others, can be, or must be selected. For example, you might want the timed event(s) to occur only on one day, Wednesday. So you would scroll until WE is in the screen, or lighted up in the screen. How you confirm that selection I don't know, since I don't have this particular timer. :) Another aspect that backs up my theory is that for the entire "pre-packaged" *Week* option, you still have to "Select MO, TU, WE, TH, FR, SA, SU". In other words, even though you want the timed event(s) to occur every single day of the week, you STILL have to select EVERY single day of the week for this option to be programmed! And the same goes for the *Weekday* and the *Weekend* options, because the listed quantity of day name abbreviations are less for each of those two options, five and two, respectively. Again, this certainly suggests that while in this area of programming, selecting the actual, individual abbreviated day names is necessary to program any of the three operations -- Week, Weekday, or Weekend. If they had just written it this way...scroll to the day(s)...it would have been a lot easier for users to recognize and understand the possible variables. The presumed logic is that by having the ability to select just one day also required, by default, selecting the multiple days for the Week, Weekday and Weekend functions. Good luck and hope this helps!

Yes

This timer comes with pretty good instructions, but it is a little difficult at first. Once you do it, it's pretty easy.

Yes, a single AA battery holds the programs and clock. It comes preinstalled; I do not know yet how long it will last but it should last a year or more.

Yes you can. Just program the on setting for the time you want it to come on, then program the off setting for 5 minutes later. Choose the next time to have it come on and repeat. Do this for event settings 1 through 5. Don't set events 6 and 7 and it will only come on 5 times.

Sure, as long as it's plugged into an electrical source changing the battery shouldn't have any effect.

The timer can be turned on manually or set to auto.