The rust formation is quite normal for the age. I would just put some protection on the engine oil pan, which seems to be corroded at the forward side. Keep an eye on the engine mounts, the one close to the thermostat housing, the rubber is partly cracked. Not that bad yet.
JEEP Grand Cherokee 4.7 Lmtd 2004
HID 8000K in low and fog / Quad Squad member
Monroe Reflex shocks / Pirelli Scorpion ATR 245/65/17 - Transgo reprogramming shiftkit.
Like they said nothing thats too concerning. Suspension, motor and tranny mounts, drivelines thats really normal. They are made of a hard and thick enough steel that they will take a very long time and lots of abuse to rust to the point of breaking. Main things to worry about are the thinner steel parts. Such as the oil pan, tranny pan and body parts. If you are really worried about it give a good coat of POR-15 to everything.
The majority of that is surface rust, just clean it all up. You can paint the parts or coat it in something like rhino liner to help protect against the winter salt and that oh so great road de-icing crap that they love to put on the roads.
2001 Silverstone Metallic WJ Limited:
Gen III Clear/Chrome Projector/CCFL Halos/LEDs, 8K HIDs, 8K HID Projector/Halo fogs, Clear/Chrome Tail Lights and 3rd Brake Light with LEDS, Diamond Mesh Upper and Lower Fascia, Spectre CAI, Breather Filter, Cabin Air Filter, Low-Temp Thermostat, Jet Stage 1 Chip, MagnaFlow Exhaust with Resonator Tip, Shorty Antenna, Front/Back De-badged