Because of Fed Cup, Venus will stay in the States at least until late april so my guess is that she will play one clay-court american tournament before that. Serena is defending FCC so Venus will probably defend Amelia ISland. She hasn't commited yet but she still has time. But if she plays Amelia Island, she probably won't play Warsaw cuz that would mean 3 consecutive weeks. And if one thing is clear is that Venus is definitely cutting her schedule ... I expect her to play one less clay event this year compared with last year.
My guess of her schedule leading to the french:
2 weeks of rest
2 weeks of rest
1 week of rest
With this kind of schedule, her #2 ranking will still be safe. Kim is 1000 pts behind and even if she wins Scottsdale tomorrow (250 pts), IW (400 pts at best cuz she'll be the highest seed) and reaches the SF in Miami (200 pts but she defends 101 there), that would still leave Kim some 300 pts behind Venus. After that, I expect Kim going back to Europe (she will have played for 4 weeks non-stop). In Europe, she will lose her pts from hamburg cuz the tournament has been canceled. She was defending champion so she will lose more pts than Venus. But I expect Kim playing Warsaw to compensate, then Berlin (no pts to defend) and Rome (defending 200 pts). I don't think she will overcome Venus by RG.
After RG, the story could be different though ... Venus has a lot more pts (600) to defend than Kim (88 pts). So if Venus doesn't win Rome or RG, she could lose her #2 ranking after RG!
She will definitely lose it after Wimbledon if somehow doesn't win at least 1 GS! kim has only 40 pts to defend there ...
I'm sure Venus is aware of that ...