1. Is there a ban on donations from foreign interests to political parties?

Source:

Article 15, Law "On Political Parties in Ukraine" (2001)

(UK)

Стаття 15, Закон "Про політичні партії в Україні" (2001): 
Не допускається здійснення внесків на підтримку політичних партій:
5) іноземними державами, іноземними юридичними особами, юридичними особами, в яких не менше 10 відсотків статутного капіталу або прав голосу прямо або опосередковано належать нерезидентам, а також юридичними особами, кінцевими бенефіціарними власниками (контролерами) яких є іноземці чи особи без громадянства;
7) фізичними особами, які не є громадянами України (іноземцями та особами без громадянства), а також анонімними особами чи особами під псевдонімом

(EN)

Donations in support of political parties shall be prohibited if they are made by:
5) foreign states, foreign legal entities, legal entities in which no less than 10 percent of the authorized capital or voting rights are directly or indirectly owned by nonresidents, as well as legal entities in which the ultimate beneficiary owners (controllers) are foreign citizens or stateless persons;
7) individuals who are not citizens of Ukraine (foreigners or stateless persons), as well as anonymous persons or persons under a pseudonym.
Available at: 

https://zakon.rada.gov.ua/laws/show/2365-14#Text

In Ukraine, foreign states, foreign legal entities, and individuals who are not citizens of Ukraine (foreigners or stateless persons) are prohibited from making donations in support of political parties.

In national (parliamentary and presidential) elections, restrictions are applied under the Law “On Political Parties in Ukraine,” which also applies during the inter-election period. In particular, Article 15 of the Law “On Political Parties in Ukraine” refers to: Part 1, 3 of Article 96 of the Electoral Code of Ukraine (restrictions on entities in presidential elections), Part 2 of Article 96 of the Electoral Code of Ukraine (restrictions on the size of contributions in presidential elections); Parts 1 and 3 of Article 152 of the Electoral Code of Ukraine (restrictions on entities in parliamentary elections), Part 2 of Article 152 of the Electoral Code of Ukraine (restrictions on the size of contributions in parliamentary elections)