Ok so in East Coast, I can suggest three major areas.
The first would be the
condos in the vicinity of Parkway Parade. That's a mall right on the coast. You can search for it on Google Maps. The
condos are generally to the west and north of it. Some places to look at are Cote de Azur, Seaview (disclaimer: not actually a 'sea view'), Esta, One Amber, and a few others in the vicinity. All of these are high rises, newer buildings, and very short walking distance to two shopping malls (Parkway, a mainstream mall like in the US, and I12 Katong, which a slightly upscale/boutiqy mall), a hawker center, and a wet market. Plus, you can walk to the beach. You're also a short walking distance to the lower half of Joo Chiat, which has a lot of boutiquey shops and trendy food places, and a longer walk to upper Joo Chiat. It has more of the same, plus some Karaoke parlors and "BMD" bars. Not exactly family establishments, but nothing that would ever offend bother most people unless you went inside. (Basically, Redlight-lite) A further walk is Tanjong Katong (maybe 1km or so), which also has good/trendy food places of a wide variety. (including best Fish n Chip in Singapore!) Equally far, about 1km to the east of PP is the Siglap area, which again, more trendy dining options. Since you mentioned coffee shops in first post, Best coffee on the East Coast is there, Vines on Nine. It's also right next to a Starbucks if by coffee you meant blended sugary beverages.
The downside is that between East Coast Parkway and Marine Parade Road, there is a lot of road noise and hustle and bustle.
The second area would be the cluster of condos at Costa Del Sol, Bayshore, and Bayshore park. These are about 2km directly east of Parkway Parade, also on the water. They're also tall, but less hustle and bustle there and a fair amount quieter. You still have car noise from East Coast Parkway, but the rest is nice. It's more remote, so everything is a farther walk. It's probably 1km east of the Siglap area I describe above; so a fair walk to most anything except the beach. There is a shuttle bus that runs from here directly to Bedok MRT and also to Parkway Parade mall though.
The last area would be Telok Kurau. It's a residential area that takes up about half of the area between Siglap and Joo Chiat. If you look on the map below, it runs along East Coast road, and then north along the Siglap park connector. Now this area is completely different. It has a lot of low rise condos mixed in with houses. It will be very quiet. Farther from the coast, but if you just want nice walks, the Siglap park connector is much more peaceful and arguably nicer. Depending how far north you go, you're quite close to Kembangan MRT. This area may not be as feasible without a car; you'd be walking half a kilometer just to a bus at least most likely.
Hopefully you like maps:
Here is the cluster of high rise condos just west of Parkway Parade
http://g.co/maps/943yh
Here is the lower half of Joo Chiat. The i12 Katong mall is at the intersection of Joo Chiat and East Coast Rd. The upper half is roughly north of Dunman/Koon Seng Rd, goes all the way to Changi Rd.
http://g.co/maps/c7npk
Siglap Area, Coffee shop is next to Starbucks and the Killiney Kopitam:
http://g.co/maps/wy3cq
Bayshore condo cluster:
http://g.co/maps/h57n8
Telok Kurau area, roughly bordered by Changi Rd on the north, East Coast Rd on the South, Still Rd on the west, and the river/canal on the east:
http://g.co/maps/kkj9c
Hopefully you're good at maps, otherwise it might be a little confusing. There is also what I consider a better map site for finding buildings in Singapore than Google Maps. Unfortunately I can't link to it. If you google for "Street Directory Singapore", you'll find it. It labels almost every building, and is much more clear to read. It doesn't have satellite view though, and is quite slow to load. Also on Google Maps, a lot of the building/business names are mislabeled. They might be across the street or down the block from where Google says they are.
Good luck!
edit: Removed some of the Singlish
