Vintage Portisch on the Huebner Nimzo-Indian(E41)

The Huebner Variation usually features blocked play and maneuvering inclosed postions. In the featured game, black takes a gambit pawn in the opening and suffers.

Portisch,Lajos (2630) - Timman,Jan H (2585) [E41]
Hoogovens Wijk aan Zee (5), 01.1978

Timman in 1992 Chessbase

'Timman was an outstanding prospect in his early teens, and at Jerusalem 1967 played in the World Junior Championship, aged fifteen, finishing third. He received the International Master title in 1971, and in 1974 attained Grandmaster status, making him the Netherlands' third after Max Euwe and Jan Hein Donner. In the same year he won the Dutch Championship for the first time, having finished second in 1972. He was to win it again on many more occasions through 1996. His first notable international success was at Hastings 1973/74, where he shared victory with Tal, Kuzmin, and Szabó.[3] A string of victories quickly followed at Sombor 1974 (with Boris Gulko), Netanya 1975, Reykjavik 1976 (with Fridrik Olafsson), Amsterdam IBM 1978, Nikšić 1978,[4] and Bled/Portorož 1979.'-Wikipedia-Jan Timman

Critical Position 1
The center is open but white is down a pawn. What should white do?

White to play

Critical Position 2
Black's pieces look congested. Is there a way to exploit this?

White to Play