Are updates planned to take full advantage of iOS 8?

Yes. A few more details here.

Are there any known problems running the current apps on iOS 8?

Aside from a couple of minor cosmetic issues, nothing that I am aware of.

A very important note regarding iCloud Sync under iOS 8

Apple made some major low-level infrastructure changes in how iCloud works. One of these is the new "iCloud Drive" which replaces the old "Documents & Data". If you update to iCloud Drive, you must update all your devices to iCloud Drive in order to sync them. You can verify if you are currently using iCloud Drive by opening the iOS Settings app > iCloud and looking to see if iCloud Drive shows ON or OFF. Also, look to see if you have a "Documents & Data" section, if not iCloud Drive has been enabled at one time, even if it is turned off now.

If your data disappears during the upgrade to iOS 8, there are two options:

1) If you are using iCloud Sync and upgraded to Apple's new iCloud Drive, wait a while and see if your data returns on its own. When you upgrade to iCloud Drive, Apple performs a one-time migration of your existing data and this can take some time, even up to an hour or more. 

2) If the above doesn't work or you aren't using iCloud, then restore your data from the Settings > General > Database Backup & Restore (within the app). 

Alarmed - long-press and/or double-tap gestures stop responding on iPad

Occasionally you might find that a long-press and/or double-tap has no effect when using Alarmed on an iPad. While this is annoying, the workaround until the next update is simple -- just switch to the other tab and back again. In other words, if you are in the Timers tab, switch to the Reminders tab and then back to Timers again. Even after doing this, the problem will eventually recur, so I apologize in advance until I get the next update out.

Alarmed - New items don't display in the list right after adding them (iPad).
Alarmed - Existing reminders don't update in the list right after editing them (iPad).

The workaround is to switch tabs (Reminder to Timers and back again), which will cause the list to refresh.