hydrogen bond

1. The strength on hydrogen bond is not determined by intermolecular or intramolecular. it is depended on the avaliability of the lone pair electrons of N, O or F atom and the partial positive charge on the H atom attached on N, O or F atom on general case. Intermolecular or intramolecular hydrogen bond only tells you the formation of hydrogen bond is with 2 different molecules or within a single molecule only.

2. The hydrogen bond is always stronger than dipole-dipole interaction since dipole-dipole interaction is only a Van der Waals' force. Both intermolecular and intramolecular hydrogen bond are stronger than that.

3. There will be hydrogen bond formed between the O atom of the carbonyl group of the ester and the hydrogen of the chloroform. Although the proton of the chloroform is not attached to the N, O or F atom, the 3 electronegative chlorine atoms withdraw electron density and make the proton carries partial positive charge comparable with the H atom attached to N, O or F atom.