You need not fear anything related to your expressed concerns. Yes, Imperial Palms had a recent refurbishment and more is underway (started in August). As part of the refurbishment, brighter colors are being used and the living room and 2nd and 3rd bedrooms are being upgraded with new LCD TVs. Other examples over the past 18 months (from a recent BOD letter to owners):
On the exterior of the resort building, parapet wood caps and hose bibs were replaced. In the common areas of the resort, new luggage carts were made available for use, hot water heaters were replaced, and the asphalt was repaired and resealed. In the villa, the granite kitchen counters were regrouted and sliding glass door rollers were replaced.
Also, the clubhouse, including the fitness center and the Marketplace Express, has been renovated. There have been other smaller enhancements, too numerous for me to list.
As for driving "behind the hotel", you would do that only if you were staying at Sabal Palms or parking for the hotel. When you enter the hotel/timeshare complex, you turn left for the front of the hotel, turn right for Imperial Palms and Royal Palms and go straight ahead - behind the hotel - for Sabal Palms and hotel parking.
This is an old property. So some exterior parts of the complex (e.g., the stairs) certainly don't look as though they were built within the past five years and they weren't. But as suggested above, this is a great place to stay!